Tenable Network Security, Inc.
Tenable SecurityCenter 4 and Components
Security Target
Version 1.0
September 13, 2012
Prepared by:
Tenable Network Security, Inc.
7063 Columbia Gateway Drive, Suite 100
Columbia, MD 21046
Prepared For:
Science Applications International Corporation
Common Criteria Testing Laboratory
7125 Columbia Gateway Drive, Suite 300
Columbia, MD 21046
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1. SECURITY TARGET INTRODUCTION...........................................................................................................4
1.1 SECURITY TARGET, TOE AND CC IDENTIFICATION........................................................................................4
1.2 CONFORMANCE CLAIMS.................................................................................................................................4
1.3 CONVENTIONS AND ACRONYMS.....................................................................................................................5
1.3.1 Conventions ...........................................................................................................................................5
1.3.2 Acronyms ...............................................................................................................................................5
2. TOE OVERVIEW ...............................................................................................................................................6
2.1 TOE DESCRIPTION .........................................................................................................................................8
2.1.1 Tenable SecurityCenter (SC4) ...............................................................................................................8
2.1.2 3D Tool (3DT) .....................................................................................................................................14
2.1.3 Log Correlation Engine (LCE) ............................................................................................................14
2.1.4 Passive Vulnerability Scanner (PVS)...................................................................................................15
2.1.5 Nessus Scanner (Nessus) .....................................................................................................................16
2.1.6 xTool (Nessus) .....................................................................................................................................16
2.2 TOE ARCHITECTURE....................................................................................................................................18
2.2.1 TOE Physical Boundaries....................................................................................................................18
2.2.2 TOE Logical Boundaries .....................................................................................................................20
2.3 TOE ENVIRONMENT.....................................................................................................................................24
2.3.1 Protection of TOE communication ......................................................................................................24
2.3.2 Non-bypassability of the TSP...............................................................................................................24
2.3.3 Domain Separation..............................................................................................................................24
2.3.4 Reliable Time Stamps...........................................................................................................................25
2.3.5 Trusted Path.........................................................................................................................................25
2.4 TOE DOCUMENTATION ................................................................................................................................25
3. SECURITY ENVIRONMENT.........................................................................................................................26
3.1 THREATS ......................................................................................................................................................26
3.1.1 TOE Threats.........................................................................................................................................26
3.1.2 IT System Threats ................................................................................................................................26
3.2 ORGANIZATIONAL SECURITY POLICIES ........................................................................................................27
3.3 SECURE USAGE ASSUMPTIONS .....................................................................................................................27
3.3.1 Intended Usage Assumptions...............................................................................................................27
3.3.2 Physical Assumptions ..........................................................................................................................27
3.3.3 Personnel Assumptions........................................................................................................................27
4. SECURITY OBJECTIVES ..............................................................................................................................28
4.1 SECURITY OBJECTIVES FOR THE TOE...........................................................................................................28
4.2 SECURITY OBJECTIVES FOR THE ENVIRONMENT...........................................................................................28
5. IT SECURITY REQUIREMENTS..................................................................................................................29
5.1 TOE SECURITY FUNCTIONAL REQUIREMENTS .............................................................................................29
5.1.1 FAU - Security Audit............................................................................................................................29
5.1.2 FIA - Identification and Authentication...............................................................................................30
5.1.3 FMT - Security Management ...............................................................................................................31
5.1.4 FPT – Protection of the TSF................................................................................................................32
5.1.5 IDS – Intrusion Detection System........................................................................................................32
5.2 TOE SECURITY ASSURANCE REQUIREMENTS...............................................................................................33
5.2.1 ADV -Development ..............................................................................................................................34
5.2.2 AGD –Guidance Documents................................................................................................................35
5.2.3 ALC –Life Cycle Support .....................................................................................................................36
5.2.4 ATE –Tests...........................................................................................................................................38
5.2.5 AVA –Vulnerability Assessment...........................................................................................................38
6. TOE SUMMARY SPECIFICATION..............................................................................................................39
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6.1 TOE SECURITY FUNCTIONS..........................................................................................................................39
6.1.1 Security Audit.......................................................................................................................................39
6.1.2 Identification and Authentication ........................................................................................................40
6.1.3 Security Management ..........................................................................................................................40
6.1.4 Security roles .......................................................................................................................................41
6.1.5 Intrusion Detection System ..................................................................................................................42
7. PROTECTION PROFILE CLAIMS...............................................................................................................43
8. RATIONALE.....................................................................................................................................................45
8.1 SECURITY OBJECTIVES RATIONALE..............................................................................................................45
8.1.1 Complete Coverage – Environmental Assumptions.............................................................................45
8.1.2 Complete Coverage – Organizational Security Policies......................................................................47
8.1.3 Complete Coverage – Threats .............................................................................................................49
8.2 SECURITY REQUIREMENTS RATIONALE........................................................................................................53
8.2.1 Security Functional Requirements Rationale.......................................................................................53
8.3 SECURITY ASSURANCE REQUIREMENTS RATIONALE....................................................................................57
8.4 REQUIREMENT DEPENDENCY RATIONALE....................................................................................................58
8.5 EXTENDED REQUIREMENTS RATIONALE ......................................................................................................58
8.6 TOE SUMMARY SPECIFICATION RATIONALE................................................................................................58
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1. Security Target Introduction
This section identifies the Security Target (ST) and Target of Evaluation (TOE) identification, ST conventions, ST
conformance claims and the ST organization.
The Target of Evaluation (TOE) is the Tenable SecurityCenter 4 and Components. It consists of the Tenable
SecurityCenter 4.4 (SC4), 3D Tool 2.0.1 (3DT), Log Correlation Engine 3.6.1 (LCE), Passive Vulnerability Scanner
3.6 for Linux/Unix and Windows (PVS), Nessus vulnerability scanner 5.0.1 (Nessus), and xTool 2.1. The TOE
consists of six (6) distinct products and the evaluated configuration includes all of the Tenable products working in
unison. Tenable‟s product suite provides an integrated environment for managing security events and vulnerabilities
where all products tie together; the scanning products are updated with new and modified plugins as appropriate for
the individual application and integrate with other third party products that are not part of this evaluation. The TOE
facilitates administration and organization of security workflow and management that includes reporting automatic
notices for affected parties, division of duties, separate access to data and update and tracking of vulnerability
closure.
The Security Target contains the following sections:
Section 1 Security Target Introduction
This section identifies the Security Target (ST) and Target of Evaluation (TOE) identification,
ST conventions, ST conformance claims and the ST organization.
Section 2 Target of Evaluation (TOE) Description
This section gives an overview of the TOE, describes the TOE in terms of its physical and
logical boundaries and states the scope of the TOE.
Section 3 TOE Security Environment
This section details the expectations of the environment, the threats that are countered by TOE
and IT environment and the organizational policy that TOE must fulfill.
Section 4 TOE Security Objectives
This section details the security objectives of the TOE and IT environment.
Section 5 IT Security Requirements
The section presents the security functional requirements (SFR) for TOE and IT Environment
that supports the TOE, and details the assurance requirements for EAL2.
Section 6 TOE Summary Specification
The section describes the security functions, represented in the TOE, that satisfy the security
requirements.
Section 7 Protection Profile Claims
This section presents any protection profile claims.
Section 8 Rationale
This section closes the ST with the justifications of the security objectives, requirements and
TOE summary specifications as to their consistency, completeness and suitability.
1.1 Security Target, TOE and CC Identification
ST Title – Tenable Network Security, Inc. Tenable SecurityCenter 4 and Components Security Target
ST Version – Version 1.0
ST Date – September 13, 2012
TOE Identification – Tenable SecurityCenter 4 and Components. The TOE consists of: Tenable SecurityCenter 4.4
plus Components: 3D Tool 2.0.1 (3DT); Log Correlation Engine 3.6.1 (LCE); Passive Vulnerability Scanner 3.6 for
Linux/Unix and Windows (PVS); Nessus Scanner 5.0.1 (Nessus), and xTool 2.1.
CC Identification – Common Criteria for Information Technology Security Evaluation, Version 3.1 Revision 3,
July 2009.
1.2 Conformance Claims
This TOE is conformant to the following CC specifications:
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 Common Criteria for Information Technology Security Evaluation Part 2: Security Functional
Requirements, Version 3.1 Revision 3, July 2009.
 Part 2 Extended
 Common Criteria for Information Technology Security Evaluation Part 3: Security Assurance
Requirements, Version 3.1 Revision 3, July 2009.
 Part 3 Conformant
 Assurance Level: EAL2 augmented with ALC_FLR.2.
 This TOE is conformant to the following Protection Profile (PP):
 Intrusion Detection System System Protection Profile (IDSSYPP), Version 1.7, July 25, 2007
1.3 Conventions and Acronyms
This section specifies the formatting conventions used in the Security Target and provides a glossary of acronyms.
1.3.1 Conventions
The following conventions are applied in this document:
 Security Functional Requirements – Part 2 of the CC defines the approved set of operations that can be
applied to functional requirements: assignment, selection and refinement.
o Assignment: allows the specification of an identified parameter. Assignments are indicated using
bold and are surrounded by bold brackets (e.g., [assignment]). However, the text is not bolded
when a CC assignment was completed by a Protection Profile from which the SFR was drawn as
part of a conformance claim, so that no assignment was exercised in writing the ST.
o Selection: allows the specification of one or more elements from a list. Selections are indicated
using bold italics and are surrounded by bold brackets (e.g., [selection]). An assignment inside a
selection is indicated using bold italics surrounded by bold italics brackets surrounded by bold
brackets (e.g., [[selection]]). However, the text is not bolded when a CC selection was completed
by a Protection Profile from which the SFR was drawn as part of a conformance claim, so that no
selection was exercised in writing the ST.
o Refinement: allows the addition of details. Refinements are indicated using bold, for additions,
and strike-through, for deletions (e.g., “… all objects …” or “… some big things …”).
 Explicitly stated Security Functional Requirements (i.e., those not found in Part 2 of the CC) are identified
with “(EXT)”.
 Other sections of the ST – Other sections of the ST use bolding to highlight text of special interest, such as
captions.
1.3.2 Acronyms
3DT 3D Tool 2.0.1
CC Common Criteria
CCTL CC Testing Laboratory
CI Configuration Item
CLI Command Line Interface
CM Configuration Management
CMP Configuration Management Plan
CVE Common Vulnerabilities and Exposures
CVS Concurrent Versioning System
DHCP Dynamic Host Configuration Protocol
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DoD Department of Defense
DoS Denial of Service
EAL Evaluation Assurance Level
EU End User (a TOE role)
EXP Explicitly stated SFR
FQDN Fully Qualified Domain Name
FSP Functional Specification
GUI Graphical User Interface
HLD High-level Design
HTTP Hyper-text Transfer Protocol
ID Identity/Identification
IDS Intrusion Detection System
IDSSYPP IDS System PP, Version 1.7, July 25, 2007.
IP Internet Protocol
IT Information Technology
ITT Internal TOE TSF Data Transfer family of FPT
LCE Log Correlation Engine 3.6.1
MGR Manager (a TOE role)
NASL Nessus Attack Scripting Language
NIAP National Information Assurance Partnership
NIDS Network IDS
NIST National Institute of Standards and Technology
NSA National Security Agency
OH Organizational Head (a TOE role)
OS Operating System
PKI Public Key Infrastructure
PP Protection Profile
PVS Passive Vulnerability Scanner 3.6 for Linux/Unix and Windows
SA System Administrator (a TOE environment role)
SAIC Science Applications International Corporation
SAR Security Assurance Requirement
SC4 Security Center 4.4
SCA Security Center Administrator (a TOE role)
SFR Security Functional Requirement
SM Security Manager (a TOE role)
SMB Server Message Block
SNMP Simple Network Management Protocol
SOF Strength of Function
SSH Secure Shell
SSL Secure Sockets Layer
ST Security Target
TASL Tenable Application Scripting Language
TCP Transmission Control Protocol
TOE Target of Evaluation
TSF TOE Security Functions
TSS TOE Summary Specification
US United States
XML Extensible Markup Language
2. TOE Overview
The Target of Evaluation (TOE) is Tenable SecurityCenter 4 (SC4) and Components: SecurityCenter 4.4, 3D Tool
2.0.1 (3DT), Log Correlation Engine 3.6.1 (LCE), Passive Vulnerability Scanner 3.6 for Linux / Unix and Windows
(PVS), Nessus scanner 5.0.1 (Nessus), and xTool 2.1. The TOE consists of only these six Tenable products, as
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shown in the Figure 1. The configuration of the TOE subject to evaluation consists of a single SC4 and at least one
instance each of the Nessus, PVS, LCE, 3DT and xTool products. Support for other intrusion detection system (IDS)
products (e.g., scanners) is provided by the product but is not part of the evaluated configuration (i.e., their security
functions were not evaluated).
Figure 1 – The Tenable products comprising the TOE.
Figure 1 shows the external interfaces to the TOE. The TOE initiates all except the user interfaces. None are used to
provide IDS information to external IT entities. The external interfaces are:
Passive Network IDS Interface – Interface to monitored networks to passively collect vulnerability information.
System Logs (SYSLOG Server) IDS Interface – Interface to monitored servers to collect IDS information. The
interface uses the SYSLOG protocol to accept events from other components of the TOE.
Nessus Scanner Interface – Interface to monitored networks to actively collect vulnerability information.
Tenable Nessus Signature and Plugin Download Server – Interface to Tenable Nessus server to download
signatures and NASL plugins that allow Nessus to detect the latest known attacks and vulnerabilities against
operating systems. The downloaded signatures and plugins are configuration data that keep the product current with
known vulnerabilities. They update the signatures and plugins that are shipped with the TOE.
Tenable PVS Signature and Plugin Download Server – Interface to Tenable PVS server to download signatures
and PRM plugins that allow PVS to detect the latest known attacks and vulnerabilities from its network perspective.
The downloaded signatures and plugins are configuration data that keep the product current with known
vulnerabilities. They update the signatures and plugins that are shipped with the TOE.
3DT User Interface – User interface to SC4 using 3DT for an enhanced view of topology and vulnerability data.
xTool User Interface – User interface to xTool for conversion of XML data files to .audit file formats used by SC4.
Web Browser User Interface – User interface to SC4 using a standard web browser with an SSL connection.
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Note that in theory, Nessus can be used independently of SC. The other components, including PVS and LCE, are
also optional components to the SC. It is assumed that all components will be configured and managed by SC and
any independent interfaces would not be used. Rather, SC4 would be used (sometimes via the 3DT component) to
integrate and centralize those component capabilities.
The TOE provides administrators with tools to facilitate network security by providing the following services:
 Vulnerability discovery and management
 Security event management and incident response
 Measuring and demonstrating configuration management
 Dynamic and static asset discovery
The TOE provides an integrated environment for managing security events and vulnerabilities. The Nessus, PVS
and LCE TOE components contain plugins (or scripts) that provide functionality specific to the TOE component.
The TOE facilitates the administration and organization of security workflow and management tasks, including
automatic reporting to affected parties, division of duties, access control for application data and update and tracking
of vulnerability closure.
Information gathered by the TOE for the above tasks is stored in databases used by SC and the LCE. The reporting,
ticketing, user interface and security model are designed to ensure that the right people in the organization can
access the information they need to make informed network security and performance decisions.
The TOE consists of the six components shown above configured as an intrusion and vulnerability detection system.
The SC4 component collects vulnerability data from one or more instances of PVS sensors and one or more
instances of Nessus scanners. It analyzes the data and presents the results to its users, with the help of one or more
instances of LCE and 3DT components. The xTool has the ability to produce audit files for use by SC4 via Nessus
scanning. This fits the IDS System structure specified in the IDSSYPP, to which this ST claims conformance, as
follows:
 IDS Analyzer: SC4 with LCE and 3DT.
 IDS Scanner: Nessus.
 IDS Sensor: PVS.
xTool audit files are generated for use by SecurityCenter, but the underlying operating system on which the xTool
runs is responsible for the audit file upload function. xTool is able to query repositories and scan results in SC4; to
do so, it authenticates to SecurityCenter over SSL on TCP port 443 using valid SecurityCenter user credentials with
permissions to perform such queries.
The TOE consists of the six software components (SC4, LCE, PVS, 3DT, Nessus, and xTool) running on hardware
and operating systems that are not part of the TOE. The components do not need to all be run on the same kind of
platform. The networks that connect these components are not part of the TOE.
The SC4 component is able to interface with additional third-party generators of IDS event data, but that capability
is not tested in this evaluation.
2.1 TOE Description
This section describes the various TOE components and how they work together.
2.1.1 Tenable SecurityCenter (SC4)
Tenable‟s SecurityCenter provides proactive, asset-based security risk management. It unifies the process of asset
discovery, vulnerability detection, event management and compliance reporting by integrating the functions of the
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other TOE components. The primary functions of SC4, operating in conjunction with the other TOE components
further described below, include1
:
 Risk management: SC4 supports risk management through the use of periodic Nessus vulnerability scanning,
continuous passive PVS vulnerability scanning, automated custom administrator notification and vulnerability
projection onto network topology.
 Threat management: LCE performs real-time IDS event aggregation and distribution, real-time IDS and
vulnerability correlation, automated alerting2
of affected administrators and projection of IDS events onto
network topology.
 Asset discovery and management: SC4 allows combining the knowledge of existing asset inventories with the
vulnerability and compliance information discovered by Nessus and the PVS. SC4 performs asset discovery
with active and passive vulnerability scanners. Resources are classified by type, location and description. It also
performs vulnerability reporting, remediation and false positive management by asset type.
 Workflow management: SC4 includes a ticketing and workflow system. Vulnerability and compliance issues
can have a ticket opened against them. Tickets can be opened for just the vulnerable system, any system having
a vulnerability or any vulnerable system in an asset group. Administrators can accept the risk on one or more
vulnerabilities or raise or lower their severity level. SC4 also determines what users should receive notification
of new tickets.
 Executive reporting: SC4 provides several methods to report and visualize vulnerability, compliance and event
data: asset lists, 3D visualization using 3DT and user customizable reports. Managers can view security threats,
risks and workflows for each business unit and group of business units. Trending reports are provided for
vulnerabilities and intrusion events. Resource allocation tracking is per business unit. The security of various
business units can be compared.
 Minimal resource impact: SC4 configuration requirements are minimal, requiring slight learning curves and
simple training requirements. Full-time passive scanning by the PVS has no direct network visibility though the
impact on network performance. Distributed active scanning by Nessus has minimal network impact. Users
interact with the TOE via a web interface and all data stays within the host network boundaries.
The SC4 TOE component can manage one or more Nessus and PVS network scanners. Scans can discover new
hosts, new applications and new vulnerabilities or verify policy compliance. Nessus scans can be scheduled and
automatically distributed to multiple scanners. SC4 manages the Nessus scanners and determines which are best
suited to scan a particular host. It can use a remote Nessus scanner to simulate what an external attacker might see
from outside the network. SC4 can manage user credentials for access control. Note that while access management
may be linked to an external LDAP or Windows Domain, this use of third party authentication is not included in the
scope of this evaluation.
The LCE receives Intrusion Detection System (IDS) events from multiple sources. It analyzes the event data against
the SC4 vulnerability database to determine whether the target of an event is vulnerable to the attack. If it is, SC4
reports the information to the relevant system administrators and (optionally) to users via e-mail. SC4 includes a set
of common audit guides created by Tenable for use in various government, financial and health care compliance
audits. SC4 captures the time that system components and vulnerabilities were first discovered and when they were
last seen. This allows users to demonstrate to auditors when security issues were first identified, what was done to
1
Note that since SC4 serves to consolidate and present a unified view of the available functions regardless of
supporting components, there has been no attempt to distinguish the functions, or aspects thereof, specifically
implemented by the SC4 component from the functions made accessible via SC4.
2
Note that each component generates alerts independently relative to the events they process. For the most part,
Nessus and PVS present their results to the other TOE components. LCE TASL scripts can be defined to issue alerts
and SC4 can issue alerts based on normalized data that it receives.
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inform system owners of their required actions (i.e., disabling an unauthorized service) and how long it took to close
an issue.
The LCE performs IDS event correlation. It can send alerts to designated, authorized SC4 users to indicate that a
protected system is being attacked, and it can be configured to only send that alert if the subject system is vulnerable
to that specific attack. Further, PVS can be configured to detect both an encrypted or cleartext interactive session
and to identify sessions by IP address, port and network protocol.
For more accurate vulnerability to IDS event correlation , SC4 should be configured to synchronize with the latest
rules engine (as described on pages 15 and 16 of the SecurityCenter 4.4 Administration Guide) and have the latest
vulnerability information as possible. If scans are not being performed often enough, performing correlation on them
could be of marginal value. Using daily scans or implementing passive network monitoring can greatly increase the
accuracy of the correlated events.
SecurityCenter stores all of its vulnerability and intrusion data into highly optimized, proprietary-format binary files.
Other data, such as organization and user data, are stored in an indexed SQLite format. SC operates one daemon,
Jobd (Job Scheduler), and issues commands via XML-RPC over SSL to Nessus scanners. When SC launches a
scan, the XML-RPC commands perform the necessary functions for scan distribution and results aggregation. When
new vulnerability checks are available, XML-RPC commands are also used to determine if scanner plugins are
updated and initiate a “push” of updates from SecurityCenter out to the remote scanners. In addition to Nessus,
commands are also used via SSL to connect to one or more Tenable PVS servers.
The Jobd process manages the scheduling of all system tasks such as launching vulnerability scans, sending email,
importing vulnerability information, generating reports and new IDS signature and Nessus plugin downloads.
SC sends all email through an external SMTP server. The administrator user configures the desired SMTP settings
including hostname, port, authentication method, secure connection and return address and the Jobd scheduler
kicks off the email process as necessary. Multiple forms of authenticated email are supported and many types of
emails can be sent such as attack alerts, text results of new vulnerability scans and scheduled PDF reports. The SC
does not have a daemon listening for incoming email.
An Apache web server is included in the product distribution but is not part of the TOE. Only the version of Apache
provided with the SecurityCenter product installation is supported by Tenable and must be used in the TOE
environment to provide and protect secure user and administration interfaces.
SC4 stores vulnerability data in proprietary format binary files, while organization and user data is stored in SQLite
database files. SC4 uses Secure Shell (SSH) to make LCE queries and Secure Copy (SCP) to transfer raw log files
from the LCE to SC4. All reporting and data analysis is performed remotely by the LCE and presented to the user by
the SC4. If the LCE discovers an anomaly or a specific type of event correlation, it sends an alert to the SC4.
The LCE can receive events directly from IDS sensors using SYSLOG and Simple Network Management Protocol
(SNMP) protocols. SC4 is configured to receive IDS signature updates via direct or proxied access to the Internet. It
can access the support sites or management consoles of the various IDS solutions it supports in order to build an up-
to-date reference model of all the signature events it might find in logs from those IDS solutions. These signatures
are pushed out to the corresponding LCE servers for IDS event correlation. Correlation of event signatures from the
various sensors is performed by matching Common Vulnerabilities and Exposures (CVE) (http://cve.mitre.org/) and
Bugtraq (http://www.securityfocus.com/bid/) IDs with Tenable Nessus and PVS plugin information. SC4 also
provides optional web-based reporting and analytical functions. SC4 uses the collected scan data to build dynamic
asset lists of system vulnerability and configuration information using dynamic rules. These lists include account
addresses, open ports numbers, specific vulnerabilities, IDs and descriptions of discovered vulnerabilities from
several known vulnerability databases. Dynamic asset lists can be augmented with existing static asset lists collected
externally to the SC4.
Although the TOE also supports a single scanner configuration (i.e., SC4 and Nessus), the evaluated configuration
of the TOE is for a multiple scanner configuration.
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For small networks (e.g., a few Class C networks), all of the vulnerability assessment components of the
SecurityCenter can be installed on a single server. When installed on a single server, the primary processes that will
be running and active include nessusd (Nessus), pvs, pvs-proxy, and pvs-proxy-service.exe
(PVS), Jobd (SC) and httpd (SC). These processes are “always-on”, while there are others that run “on
demand” at various times.
XML-RPC commands from SC manage the results from the Nessus daemon. The Nessus server runs the Nessus
daemon on TCP port 8834. The server will also typically run the Apache web server on TCP port 443, as well as
SSH on TCP port 22.
SecurityCenter, Nessus and PVS installed on a single server
This configuration supports multiple organizations and can conduct and store scans for a fairly large group of users.
It does not, however, take advantage of more than one Nessus or passive scanner. In addition, it does not make use
of the event processing of the LCE.
Depending on the size of the scanned network, it may suffer performance problems while conducting a scan. For
example, when no scans are occurring, the Apache web server has a majority of the system resources to provide fast
responses to user queries about the current network vulnerabilities. However, when a scan is occurring, the scan
daemon will consume a noticeable amount of system resources. A dual CPU system will help, but placing the scan
daemon(s) on a separate system is the best way to limit the impact to SecurityCenter.
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All functionality of SecurityCenter is available, even though only one server is being used. Nessus network scans
can be scheduled as often as desired, with or without credentials. One or more SecurityCenter users can be created,
each with different roles and data access. Reports can be scheduled and so on. The only functionality lost with a
single server architecture is load balanced scanning or any type of scan that required multiple scanners.
SecurityCenter users employ their web browser to access their security information. These users can be within the
network, coming across a VPN or anywhere else they have network access.
Multiple Scanner Architecture
Expanding the above architecture, multiple Nessus and PVS systems can be added for each Class C subnet to be
scanned. To add these devices to SecurityCenter, they should first be installed in their desired locations and then
entered into the SecurityCenter configuration by the administrator.
In the diagram below, SecurityCenter is deployed on a server in the lower right and multiple Nessus scanners are
deployed across the small network. The icons show four PVS systems deployed on various network links.
SecurityCenter and multiple Nessus/Passive Vulnerability scanners
In this configuration, when an active scan occurs, the targets get split up between the active scanners. During active
scans, the CPU usage on the SecurityCenter server is very minimal. When all scanning is performed by remote
Nessus scanners, the overhead from using XML-RPC commands to the Nessus scanners is minimal.
Since multiple scanners with different processors are used to conduct scans, the scans finish more rapidly than using
a single scanner. Console users will not see a difference in the vulnerabilities reported, but they will see much less
network impact and their scans will complete several times faster than previous scans.
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Vulnerability data from PVS is handled differently. Since it is running 24x7, it is configured to record vulnerability
data and send it to SecurityCenter once an hour by default. SecurityCenter will save any passive vulnerability data
for 7 days by default. Vulnerability data from a PVS automatically shows up on SecurityCenter and populates its
knowledge of network vulnerabilities.
With this distributed architecture, the Nessus scanners can also be used to target networks other than what they scan
for by default. In the above network, each Nessus scanner would have been associated with their default target
networks and this is called a “zone”. SecurityCenter scans can be configured to override default zones and ask, for
example, the Nessus scanner in the upper portion of the network, to scan the network segment on the bottom. This
type of “zone” scanning allows for testing of firewall policies and exercising network IDS sensors.
Single Log Correlation Engine Architecture
SecurityCenter capability can be extended with one or more LCEs. This engine can be deployed either on the same
or a separate server and can receive logs from many different devices including IDS/IPS devices. All logs are sent to
the LCE and very little data is sent back to SecurityCenter.
Example SecurityCenter and Log Correlation Engine
In the above network diagram, the SecurityCenter and the single LCE are placed on two different servers.
Although not shown, dozens of LCE agents can be placed on key servers and at network choke points to aggregate
as many logs as possible. The agents would connect back over TCP port 31300 to the LCE. Devices that can
generate SYSLOG messages can also be sent to the LCE. This SYSLOG data can also include IDS data from a wide
variety of intrusion detection devices. Other supported protocols include SNMP, SDEE, RDEP, and OPSEC.
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SecurityCenter communicates with the LCE through secure SSH and SCP connections. All reporting and data
analysis is presented through the SecurityCenter UI, but performed remotely by the LCE. If the LCE discovers an
anomaly or a specific type of event correlation, it can send a message to SecurityCenter that treats the alert as if it
came from an intrusion detection device.
SecurityCenter users can analyze any normalized log and correlated events obtained by the LCE with the same
rights the user has to look at vulnerabilities. Users with the appropriate role-based permissions automatically have
this access.
Multiple Log Correlation Engine Architecture
SecurityCenter can make use of more than one LCE. A single SecurityCenter can have as many organizations as
desired. Each organization can also have its own LCE.
From the SecurityCenter‟s point of view, it really does not matter how each remote LCE is configured. One LCE
could be focused completely on long-term NetFlow monitoring, another on firewall logs and another on application
logs from Exchange, the SQL farm and the Citrix server.
2.1.2 3D Tool (3DT)
3DT is a 3D visualization tool that runs on a user workstation and displays network topology and the relative
distribution of security information in three dimensions. It runs on Windows and requires a SecurityCenter account
to access the data. Its only form of communication with SecurityCenter is via an SSL communication path. During
3DT configuration with a SecurityCenter, after clicking “Test Login” for the first time, a certificate warning is
displayed for the remote SecurityCenter. If the remote host is known and trusted, the warning is acknowledged to
perform the login. Users launch the 3DT tool, establish an SSL connection with SecurityCenter and then
authenticate to the SecurityCenter through a valid SecurityCenter user account. It supports three reporting modes:
node traits, connections and counts. 3DT users can make one or more queries to populate the 3DT data sets and the
tool plots topology data for discovered routing and devices, interconnections and correspondence among network
servers and clients. Two data sets can be compared using this tool. 3DT plots and explores the results of one query
against another and allows the browsing of data (events) and topology. It also provides rapid visual feedback about
event frequency.
2.1.3 Log Correlation Engine (LCE)
LCE aggregates, normalizes, correlates and analyzes event log data from the various devices within the network
infrastructure. It is closely integrated with SecurityCenter, allowing the centralization of log analysis and
vulnerability management.
Each SecurityCenter can manage multiple LCEs and each LCE can receive system logs, netflows, IDS events,
firewall events, honeypot events and other types of records from multiple sources. Only Nessus scanner and PVS
IDS sources are included in the evaluated configuration, however. SecurityCenter users see only the LCE events
they are authorized to see.
The LCE implements a SYSLOG interface that it uses for the purpose of accepting events to analyze and correlate.
While LCE could potentially accept SYSLOGs from multiple sources, the TOE includes LCE agents for specific
OSs (including the TOE component hosts) that serve to monitor those systems and generate SYSLOG findings to
LCE. When an LCE receives an event, it can save the raw event data, and it can also perform customized analysis on
it. When an event is sent to SC4, the data is normalized and forwarded. The LCE enables the SecurityCenter to
perform high-speed analysis and reporting for many types of events.
The LCE includes an event scripting language, based on Tenable‟s Nessus NASL language, known as Tenable
Application Scripting Language (TASL) that can be used to specify complex correlation tasks for execution in real
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time. TASL scripts can be written or installed by any of the system administrator roles, but can be executed only on
the network segments to which each system administrator has access.
LCE allows SC4 functionality to be expanded to any log device, where the primary focus is to offload aggregation,
normalization, analysis and reporting of security events to one or more servers other than the SC4. SC4 can be
extended with one or more LCEs. The LCE can run on a separate server from the SC4. LCE can collect events using
a SYSLOG interface and can make use of other generic protocols for behavioral and event correlation and can send
the alerts to the SC4. The SC4 monitors the status of each LCE server attached to it so that any system failure can be
quickly investigated.
LCE includes client agents for Unix, Windows, NetFlow, OPSEC, RDEP/SDEE and network sniffing that can be
used to log a variety of network traffic. LCE clients can be placed on key servers and at network choke points to
aggregate as many logs as possible. The LCE‟s default behavior is to monitor each host with a client, including
client or server behavior, inbound, outbound and Internet connection rates and per event rates.
Although the TOE can be configured to accept IDS events from other sources, the evaluated configuration only
includes the Tenable IDS event sources that are part of the TOE. This restriction is enforced by the ability to filter
event sources based on IP address.
In the evaluated configuration, the LCE is configured such that it is used only via the SC4. In relation to the
evaluated configuration, the LCE GUI may not be used for regular operational activities in the role of a TOE
component.
2.1.4 Passive Vulnerability Scanner (PVS)
PVS continuously monitors network traffic, searching for vulnerable systems, watching for potential application
compromises, observing client and server trust relationships and tracking open or browsed network protocols in use.
PVS monitors network traffic for a variety of security related information including:
 Client and server application vulnerabilities
 Detection of compromised or subverted applications
 Detecting when new hosts are added to the network

 Highlighting all interactive and encrypted network sessions
 Tracking exactly which systems communicate with other internal systems
 Detecting which ports are served and which ports are browsed for each individual system
 Passively determining the type of operating system of each active host
SC4 fuses this information with the active or credentialed scan results from Tenable‟s Nessus vulnerability scanner.
Note that the period of PVS logging is configured and SC4 gets the available data when it connects for that purpose.
As such, PVS and SC4 should be coordinated appropriately. SC4 communication is facilitated via a proxy enabling
the use of web-based SSL interactions. When a credentialed scan is performed the credentials are protected by the
SSL channel.
PVS is not a typical Network IDS (NIDS) in that it does not run large signature sets of known network attack or
probe activity. Instead, as the PVS learns about a network‟s applications, it looks for compromise events in traffic
originating from those systems. PVS detects when systems are compromised based on application intrusion
detection; selectable rule libraries and filtering rules to look for overflows, web attacks or other traffic and sniffs out
vulnerabilities from network session traffic. Most protocols carry internal version and identity information.
PVS includes a scripting language called PASL, which stands for the “Passive Analysis Scripting Language” and is
a library based on TASL (the Tenable application scripting language) and NASL (the scripting language used for
Nessus vulnerability scanner scripts), but independent from the Nessus backend. The format is similar to that used
for writing NASLs for the Nessus vulnerability scanner, making it easier for those familiar with writing NASLs to
write event correlation algorithms for events in the LCE. Specifically, PASL contains all functionality of TASL,
along with all knowledgebase features of NASL.
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PVS uses its own signatures and plugins for passive analysis (i.e. it does not have an agent on any of its targets). It
can collect information about client-side and server-side vulnerabilities, detect rogue and non-routable hosts,
discover network assets by active IP address, detect TCP SYN packets (indicating client-side usage and providing
passive OS fingerprinting) and TCP SYN-ACK (open services and “show-connections”). PVS is constantly
updating its model of the networks it is monitoring, noting which hosts are active; which ports are open; and which
plugins have matched on particular IP address.
Note that while the PVS could be configured to share its scanned data with alternate or multiple clients, the
evaluated configuration restricts its sharing to other TOE components, specifically the SC4 and LCE. Similarly,
while the PVS can be configured to forward vulnerability and alert data via SYSLOG to non-TOE components, this
capability is disabled in the evaluated configuration. If the PVS is being used as a vulnerability source, it can be
configured to send its data directly to the SC4. Once the vulnerability data is on the SC4, it is pushed down to the
LCE for correlation. If PVS is being used as a pseudo IDS source, it can be configured to send its data directly to the
LCE for correlation that can be accessed on demand from the SC4.
Furthermore, PVS can be configured to take actions to mitigate some IDS-related events. For example, it can send
TCP resets when disallowed traffic is detected. However, given that the enforcement of such directives is outside the
control of the TOE this feature has not been subject to security claims and as such has not been evaluated in this
regard.
In the evaluated configuration, the PVS is configured such that it is used only via SC4. In relation to the evaluated
configuration, the PVS CLI is only used for initial installation and configuration of the product and for any technical
support issues where use of the CLI is required for failure recovery. The PVS CLI may not be used for regular
operational activities in the role of a TOE component.
2.1.5 Nessus Scanner (Nessus)
Nessus is an active scanner that provides agent-less host auditing of both UNIX and Windows servers. It features
network node discovery, asset profiling and vulnerability analysis. Nessus scanners can be distributed throughout a
large network, on DMZs and across distributed networks. It can be used for ad-hoc scanning, daily scans and quick-
response audits. When managed with SC4, vulnerability recommendations can be sent to responsible parties,
remediation can be tracked and security patches can be audited.
Nessus discovery scans include ARP ping, SYN ping, ICMP ping, TCP CONNECT (full TCP handshake), SSH
netstat, WMI netstat, SNMP and TCP SYN. OS detection methods include port scanners that send packets in a
specific way and listen for minute changes that would identify the type of server responding. Service detection
scanning identifies servers by the banners they present and how they respond to probes. Vulnerability analysis scans
servers for known vulnerabilities using the information about the server resulting from the port scanner, OS
detection and banner detection routines. The Nessus architecture has the flexibility to deploy the scanner in multiple
configurations and with various reports to reflect the risk level of each security vulnerability found (i.e., from Low
to High) and provides guidance on how to prevent them from being exploited.
Scan types include:
 Local (credentialed): Providing target system credentials to Nessus will allow it to find local information from
a remote host. Nessus scans the local host for security vulnerabilities, identifying missing security patches,
checks client software versions and audits policy compliance using a valid logon on the target machine. A local
scan is less intrusive than a network scan and can provide information about installed software.
 Remote (network): Nessus scans remotely for vulnerabilities using its standard methodology of port scans
followed up by vulnerability scans. It can identify open ports, recognize underlying OSs and discover
vulnerabilities in network services.
 Hybrid (both network and credentialed): A combination of local and remote scans that provides the most
comprehensive scan of a network host.
Nessus contains service-specific plugins that determine the services that are running behind specified ports, based on
defined parameters. This minimizes the impact of security scans on printers and other devices that cannot support
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multiple open ports simultaneously. Nessus contains more than 48,000 plugins, each of which checks for one or
more unique vulnerabilities across dozens of operating systems and hundreds of different software packages and
provides scan results based on these checks. Plugins are organized into families for convenience and optimizing
scans. While this evaluation addresses whether specific Nessus plugins can be selected and exercised, the evaluation
does not determine the efficacy of any one specific plugin or plugin family.
The administrator can opt to enable all security checks or to enable all security checks except the checks that are
potentially harmful. Administrators also have options to define new security check policies and to activate a pre-
defined policy.
Nessus reporting focuses on the severity of vulnerabilities. Warnings are mild flaws or vulnerabilities that may
increase the severity of other vulnerabilities. Holes are severe flaws or vulnerabilities that may have a major impact
on host or network security. The severity ratings are derived from the associated CVSS score, where less than 5 is
“Low”, less than 7 is “Medium”, 10 or less is “High” and a CVSS score of 10 can be flagged as “Critical” if so
desired. Nessus security reports can be displayed as a new web browser instance. All reports are archived and
available for later viewing, printing or comparing with other reports.
Nessus can save all of its vulnerability data in various file formats (notably XML and HTML). The Nessus scanner
includes the Nessus Attack Scripting Language (NASL) designed to allow the development of new security tests
easily and quickly. NASL scripts can be written or installed by any of the system administrator roles, but can be
executed only on the network segments to which each system administrator has access.
Nessus can be invoked as a command on a host system shell. This command line interface (CLI) support allows
arguments on the command line so that scans can be launched via batch files or scripts. This provides support for
concurrent scanning because each CLI runs as a separate process. CLI reports can be saved as NESSUS, HTML and
TXT formats.
In the evaluated configuration, Nessus is configured such that it is used only via SC4. As such, SC4 utilizes the
Nessus CLI and references to the administrator, as stated above, apply to the SC4 administrator and not a Nessus-
specific role. In relation to the evaluated configuration, the Nessus CLI is only used for initial installation and
configuration of the product and for any technical support issues where use of the CLI is required for failure
recovery. The Nessus CLI and the Nessus Server Manager GUI (an additional server management interface) may
not be used for regular operational activities in the role of a TOE component. While Nessus could be configured for
multiple means of user authentication, the evaluated configuration includes only the use of passwords for
authentication. This account information is configured within the SC4 for the purpose of interacting with the Nessus
component(s).
2.1.6 xTool
Tenable designed the xTool to work with the official XCCDF Tier IV content used in the FDCC program. Beta
quality XCCDF-compliant content (Tier 3 and below) is also available from NIST. SecurityCenter users can obtain
the various SCAP bundles at http://nvd.nist.gov/fdcc/download_fdcc.cfm . Bundles can be downloaded collectively
as a single .zip archive, or separately based on SCAP bundle types (IE 7, Vista, Windows XP, Vista Firewall, XP
Firewall, Windows 7, Windows 7 Firewall, IE8). The xTool is capable of generating .audit files from XCCDF and
OVAL content, and can also convert .nessus report files to XCCDF and OVAL output.
In the evaluated configuration, xTool is configured on a Windows operating system and can authenticate to
SecurityCenter for queries over SSL on TCP port 443. Its only form of communication with SecurityCenter is via an
SSL communication path. During xTool configuration with a SecurityCenter, after clicking “Test Login” for the first
time, a certificate warning is displayed for the remote SecurityCenter. If the remote host is known and trusted, the
warning is acknowledged to perform the login. Audit files or output files are generated by xTool, but the underlying
operating system is solely responsible for the upload of all files to SecurityCenter for use in configuration auditing.
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2.2 TOE Architecture
This section describes the TOE physical and logical boundaries.
2.2.1 TOE Physical Boundaries
The TOE physical boundary includes the following components:
 SC4 – Tenable SecurityCenter 4.4
 3DT – 3D Tool 2.0.1
 LCE – Log Correlation Engine 3.6.1
 PVS – Passive Vulnerability Scanner 3.6 for Linux/Unix and Windows
 Nessus – Nessus Scanner 5.0.1
 xTool – xTool 2.1
Each bulleted item is licensed separately, except for the 3DT and xTool, which do not require a license. The
following sub-sections describe the platforms supported for each of the TOE components. These platforms are part
of the TOE environment, not part of the TOE. Each system must be dedicated to the appropriate Tenable
applications (SecurityCenter, Nessus, LCE or PVS) and contain no other applications except what is required to
operate the system in a secure manner. Tenable applications can co-exist on the same host.
2.2.1.1 SC4
SC4 consists of the Tenable SecurityCenter 4.4 software component.
SecurityCenter 4 is available for Red Hat Enterprise Server 4 (32-bit only), 5 and 6 (32/64-bit). CentOS 5.3 (32/64-
bit) is also officially supported. It must be configured with a Fully Qualified Domain Name (FQDN).
SC4 installation requirements:
Scenario Recommended Hardware
SC4 and Nessus Scanner 5.0.1
managing 500 to 2,500 active IPs
CPU: 1 dual-core 2 GHz or greater CPU
Memory: 2 GB RAM (4GB RAM recommended)
Hard drive: 80 GB at 7,200 rpm (160 GB at 10,000 rpm
recommended)
SC4 managing 2,500 to 10,000 active
IPs
CPU: 1 dual-core 3 GHz CPU (2 dual-core
recommended)
Memory: 4 GB RAM (6 GB RAM recommended)
Hard drive: 80 GB at 10,000 rpm (160 GB at 10,000
rpm recommended)
SC4 managing 10,000-25,000 IPs CPU: 2 dual-core 3 GHz CPU (1 quad-core
recommended)
Memory: 6 GB RAM (8 GB RAM recommended)
Hard drive: 160 GB at 10,000 rpm (250 GB at 15,000
rpm with striped RAID recommended)
SC4 managing more than 25,000
active IPs
CPU: 2 dual-core 3 GHz CPU (4 dual-core
recommended or 2 quad-core 3GHz CPU)
Memory: 8 GB RAM (12 GB RAM recommended)
Hard drive: 250 GB at 15,000 rpm (500 GB at 15,000
rpm with striped RAID recommended)
2.2.1.2 3DT
3DT consists of the Tenable 3D Tool 2.0.1 software component.
3DT is supported for installation on the following platforms: Windows 2000, Windows Server 2003, Windows
2008, Windows XP Professional, Windows Vista, and Windows 7.
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2.2.1.3 PVS
PVS is the Tenable Passive Vulnerability Scanner 3.6 software component, which can be installed on Red Hat Linux
ES4, ES5, and ES6 (32-bit and 64-bit), and CentOS 5 and 6 (32-bit and 64-bit), Windows XP Professional,
Windows Server 2003, Windows Server 2008, Windows Vista and Windows 7. It can be deployed on existing
network IDS devices, firewalls, e-mail servers, Dynamic Host Configuration Protocol (DHCP) servers, etc. without
effecting the underlying system‟s operation. It can also be deployed as a stand-alone device for dedicated
monitoring.
PVS hardware guidelines are depicted in the following table:
Scenario Recommended Hardware
Passive Vulnerability Scanner
managing 20,000-50,000
hosts
CPU: 1 single-core 2 GHz CPU
Memory: 2 GB RAM (4 GB RAM recommended)
HDD: 72 GB at 7,200 rpm (72 GB at 10,000 rpm recommended)
Passive Vulnerability Scanner
managing in excess of 50,000
hosts
CPU: 1 dual-core 3 GHz CPU (2 dual-core recommended)
Memory: 2 GB RAM (4 GB RAM recommended)
HDD: 72 GB at 10,000 rpm (72 GB at 15,000 rpm recommended)
2.2.1.4 LCE
LCE consists of the Tenable Log Correlation Engine 3.6.1 software component. The server component is supported
for installation on the following platforms: Red Hat Linux ES3, ES4, ES5 for 32-bit platforms (4.x and 5.x for 64-bit
platforms).
Number of Events Recommended Memory Size
<2 million 1 GB
2-10 million 2 GB
10-50 million 4 GB
50-80 million 8 GB
90+ million 16 GB
Number of Events Recommended CPU
<1 million 1 single-core 3 GHz CPU
1-2 million 1 single-core 3 GHz CPU (10,000 rpm disk recommended)
2-10 million 1 dual-core 3 GHz CPU (15,000 rpm disk recommended)
10-50 million 2 single-core 3 GHz CPU (striped RAID disk is recommended)
50-80 million 2 dual-core 3 GHz CPU (striped RAID disk is recommended)
90+ million 4 dual-core 3 GHz CPU (striped RAID disk is recommended)
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2.2.1.5 Nessus
Nessus server includes the Nessus Scanner 5.0.1 software component. It is supported for installation on the
following Windows, Unix and Unix-like systems:
 Windows: Windows XP, Server 2003, Server 2008, Server 2008 R2, Vista and Windows 7 (i386 and x86-64).
 Unix:FreeBSD 9 (i386 and x86-64)
 Unix-like:
 Debian 6 (i386 and x86-64)
 Fedora Core 16 (i386 and x86-64)
 Mac 10.6 and 10.7 (i386, x86-64, ppc)
 Oracle Linux 5 (i386 and x86-64)
 Red Hat ES 4 / CentOS 4 (i386)
 Red Hat ES 5 / CentOS 5 (i386 and x86-64)
 Red Hat ES 6 / CentOS 6 (i386 and x86-64) [Server, Desktop, Workstation]
 SuSE 10(x86-64) and 11 (i386 and x86-64)
 Ubuntu 8.04 , 9.10, 10.04, 10.10, and 11.10 (i386 and x86-64)
2.2.1.6 xTool
xTool consists of the xTool 2.1 software component.
xTool is supported for installation on the following platforms: Windows Server 2003, Windows 2008, Windows XP
Professional, Windows Vista, and Windows 7.
2.2.2 TOE Logical Boundaries
This section identifies the security functions that the Tenable TOE provides.
The following features are exclusions, assumptions, or configuration restrictions in the TOE evaluated
configuration:
 Assumption: The evaluated configuration requires at least one instance of each identified TOE component.
Rationale: This is necessary in order to evaluate the interaction between the TOE and all associated
components.
 Exclusion: Use of Nessus, PVS or LCE components directly rather than via the SC4 interfaces is excluded
from the evaluated configuration. Rationale: This is necessary in order to evaluate the communications
between the TOE and all associated components.
 Exclusion: Use of third party authentication servers, such as LDAP, is not allowed in the evaluated
configuration. Rationale: The TOE provides its own means of authentication and the PP requires the TOE
to perform authentication.
 Exclusion: Custom roles are unique to each individual Organization and thus are excluded from the
evaluated configuration. Rationale: Custom roles are not pre-defined within the TOE and thus are outside
of the scope of the PP.
 Configuration restriction: Exporting data (from any TOE component) via SYSLOG outside the TOE is not
allowed in the evaluated configuration. Rationale: Monitoring data and functions outside of the TOE is
outside the scope of the PP.
 Exclusion: The LCE clients that operate within non-TOE components have not been subject to the
evaluation. Rationale: While their impact on their respective hosts is uncertain, they cannot impact the
security claims in this ST and as such are not forbidden in the evaluated configuration.
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 Exclusion: The PVS‟s inability to interfere with network traffic has not been subject to the evaluation.
Rationale: Note that while this function simply has not been subject to specific evaluation claims, it does
not interfere with the security of the TOE or its claimed functions and therefore can be used in the
evaluated configuration. This function simply has been evaluated only to the extent that it does not interfere
with other functions and not relative to explicit security claims of its own.
2.2.2.1 Security Audit
The TOE generates audit events for the basic level of audit. (Note that the IDS_SDC.1 (EXT) and IDS_ANL.1
(EXT) requirements address a different audit mechanism that records the results from IDS scanning, sensing and
analyzing tasks. This is not that mechanism.) The TOE provides a SC4 GUI that is used by authorized system
administrators to read the audit trail and to sort audit data. Authorized system administrators are also able to sort
through audit data using operating system command such as „grep‟, „awk‟, and „sed‟. The TOE restricts access to the
audit trail to authorized system administrators. When SC4 audit logs are sent to the LCE, specific audit events can
be selected for viewing by the SC4 Analysis Tool‟s “Raw Syslog Data” option through the configuration of a built-
in PRM file.
The TOE installation guides advise the systems administrator how to configure and manage the TOE security audit
storage so that storage exhaustion is prevented. Depending on settings, if audit trail storage becomes exhausted, the
TOE will prevent auditable events, except those taken by a system administrator with administrative privileges on
the TOE system.
All systems running TOE components must have the LCE client installed and configured to send event data to the
LCE server with the system_monitor.tasl script installed. This script will generate an alert if system resources
(memory, disk, CPU) reach a specified threshold that could negatively impact TOE performance. Should these alerts
be ignored and systems resources become exhausted, individual TOE component functionality may be adversely
affected.
2.2.2.2 Identification and Authentication
TOE users are required to login with a unique name and password in order to access the TOE. Only systems
administrators have access to security management functions. The TOE maintains user identities, authentication
data, authorization information and role association. The SC4 provides a web-based logon and users must be
successfully identified and authenticated prior to accessing this information.
2.2.2.3 Security Management
SC4 restricts the ability to manage functions based on the user role. The predefined roles supported by the SC4 are
SecurityCenter Administrator (SCA), Organization Head (OH), Manager and End User (EU), (which collectively
conform to the IDSSYPP Authorized Systems Administrator role). A Systems Administrator (which conforms to the
IDSSYPP Authorized Administrator role) manages the environment. It is up to the TOE user organization to
appropriately assign people to roles.
Small organizations may assign multiple roles to the same person. Larger organizations may assign roles based on
their organizational structure. For example, a large organization might give responsibility for all SecurityCenter
Administration functions and any activity that requires administrative (privileged) access to the operating system to
the Information Technology group, responsibility for enterprise management of security functions throughout the
business units, including the performance of all SC4 administration tasks to the Information Security group. If the
business unit is an Organization Head or Organization, an Information Security Officer in the business unit may be
responsible for all security functions within that unit and would serve as the Manager for that business unit. A large
organization might have multiple Managers or Organization Heads depending on Organizational units.
Within the business units, End Users may be designated. These End Users are managed by the unit‟s Manager and
are responsible for a particular network segment.
User access is restricted by the role to which the user is assigned and the assets to which the user has been granted
access. The role indicates what functionality (i.e., which menu options) the TOE presents to each user. The assets
are the machines for which the user can launch IDS scans and access IDS audit records. The SC4 component
provides the tools necessary to define users and configure access.
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SC4integrates repositories of vulnerability data that are shared as needed among users and organizations based on
manager-defined assets. The use of repositories allows for scalable and configurable data storage for organizations.
Repositories can also be shared between multiple SecurityCenters. Repositories are configured by the administrative
user and made available to the Organization Head to assign to users as needed.
There are three types of repositories: “Local”, “Remote” and “Offline”. Local repositories are active repositories of
SC4 data collected via scanners attached to the local SC4. Remote repositories contain IP address and vulnerability
information obtained via network synchronization with a second (remote) SC4. Offline repositories enable SC4 to
obtain repository data via manual export/import from a remote SecurityCenter that is not network-accessible. If
separation of data is required between two different organizations, separate repositories assigned to each
organization is used for access control. The underlying operating system limits access to the “tns” user but the SC4
product actually performs access control on its users.
A description of the roles supported by the SecurityCenter follows:
Security Center Administrator (SCA)
The SecurityCenter Administrator role is able to configure and manage the SC4 application. No access to the
underlying operating system platform is required. All functions can be performed through the SC4 GUI. The SCA
defines and manages organizations, specifying which network ranges within which network traffic may be
monitored for each Organization. Each Organization has a unique name and serial number. There are three
Organization roles: the Organization Head, Manager and End User.
The SecurityCenter Administrator‟s role includes performing the following functions:
 Manage the SecurityCenter
 Managing SecurityCenter Organization Accounts
 Managing SecurityCenter Components
 Monitoring SecurityCenter Audit Logs
The SecurityCenter Administrator (SCA) cannot access Organization data nor initiate IDS scans.
Organization Head (OH)
The Organization Head (OH) has full rights for the entire network space of an organization and cannot be deleted
without removing the entire organization entry. The Organization Head may define additional users for the address
space as either Managers, End Users or custom roles. The Organization Head is typically the security representative
for the Organization and is responsible for its overall security posture.
An Organization Head can access only one organization‟s data and can initiate IDS scans on only one
Organization‟s network.
Manager
The Manager has the same rights as the Organization Head. There can be many Managers for an Organization, but
only one Organization Head.
A Manager can access only one Organization‟s data and can initiate IDS scans for only one Organization.
End User (EU)
The End User is typically a system or network engineer who has responsibility for running a network. The Manager
and End User roles are limited in several ways:
 Each can only see vulnerabilities, IDS events and logs for a specific range of IP addresses, determined by
the particular asset lists a user has access to.
 Managers can add, edit and delete new users that may be either security managers or end users.
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 Each type of user may be able to conduct vulnerability scanning of their networks, but both types of
accounts can also be “locked out” from scanning either manually or when the threshold for failed login
attempts is reached.
 Managers can open tickets for which vulnerabilities need to be mitigated and end users can close tickets
assigned to them by marking them as fixed. Opening and closing tickets is not a security function.
An End User (EU) can initiate IDS scans on only a part of one Organization‟s network and can access only the data
relevant to that part of the one Organization‟s network.
System Administrator (Environmental Role)
The System Administrator manages the TOE environment and is the person responsible for installing and
maintaining the platform operating system on which the SecurityCenter runs. The Systems Administrator has
administrative (“root”) access to the underlying operating system, but does not have access to any SecurityCenter
user accounts. System Administrator is not a TOE role, but because the System Administrator has root access to the
operating system, that role is capable of accessing and changing anything in the TOE, including audit data. This role
includes all standard System Administration duties, such as the following:
 Operating System Installation
 System Security Hardening
 System Configuration
 Installation of Supporting Applications
 Managing User Access to the OS platform
 Installation of the SecurityCenter Software
 Installation of the SecurityCenter Components (Nessus, PVS, LCE)
 Installation of Client Applications
 OS System Monitoring
 Security Administration of the System
 System Backups
 Generate SSH keys on remote hosts for credential scans
The following table summarizes the TOE roles and the security functions they can perform. The Authorized
Administrator and Authorized System Administrator roles are required by the IDSSYPP.
Security Function
Authorized
Administrator4
Authorized
System
Administrator5
Organization Accounts
Organization
Head /
Manager
End
User
Install and configure SC41
X
Manage Organization
accounts2 X
Manage user accounts2
X
Manage SC4 components2
X
Monitor SC4 logs3
X X
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Manage audit functions2
X
Monitor audit data3
X X
1
Maps to the IDSSYPP “Query and modify all other TOE data” function.
2
Maps to the IDSSYPP “Modify Behavior of system data collection, analysis and reaction” function.
3
Maps to the IDSSYPP “Query and add system and audit data” function.
4
This role is required by the IDSSYPP to administer the platforms that support the TOE. It is a role supported
by the environment here.
5
This role is required by the IDSSYPP to administer the IDS. It is equivalent to the SC4 “SecurityCenter
Administrator” role.
2.2.2.4 Protection of the TSF
The TOE protects itself and ensures that its policies are enforced in a number of ways. While there is dependence on
the underlying operating system to separate its process constructs, enforce file access restrictions, and to provide
communication services, the TOE protects itself by keeping its context separate from that of its users and also by
making effective use of the operating system mechanisms to ensure that memory and files used by the TOE have the
appropriate access settings. Furthermore, the TOE interacts with users through well-defined interfaces designed to
ensure that its security policies are always enforced.
2.2.2.5 Intrusion Detection System
The TOE collects network traffic data for use in scanning, sensing and analyzing functions with the SC4. The TOE
performs signature analysis on collected network traffic data and records corresponding network traffic event data.
Reports are generated using a web-based interface to SC that provides the ability to examine analytical conclusions
drawn by the TOE that describe the conclusion and identifies the information used to reach the conclusion. Note that
users can only access reports via a web browser where access to TOE data is based on identification and
authentication. The TOE provides the ability to generate alarms and notify a system administrator using a configured
notification mechanism when an intrusion is detected.
2.3 TOE Environment
The TOE relies on the environment to provide the following security functionality:
2.3.1 Protection of TOE communication
The environment must protect the communication among TOE components. The TOE is shipped with an
implementation of OpenSSLv 0.9.8u. For most communication paths, the TOE must be configured to use the SSL
protections provided in OpenSSL to protect network traffic between TOE components from disclosure and
modification. The one exception is that communication between the SC4 and the LCE is performed using SSH and
SCP (over SSH). The SSH encryption is also supported using the OpenSSL module.
2.3.2 Non-bypassability of the TSP
The TOE must be deployed on a network in such a way that it can monitor all potentially malicious traffic, including
any network traffic used to administer the TOE itself. It must ensure that no traffic can circumvent the TOE‟s
monitoring functions and thus escape being monitored for malicious content.
2.3.3 Domain Separation
The TOE components run as separate processes in one or more operating systems. However, this separation is not
used to separate users with different access rights. Users of the TOE are not provided access to operating system
shells nor are they able to run arbitrary programs on the operating system as a result of their TOE access. The TOE
controls user access through the functionality provided on its user interfaces.
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2.3.4 Reliable Time Stamps
The TOE environment provides a source of reliable time stamps through the host systems included in the TOE,
which the TOE uses in its audit function. The system administrator needs to be aware that use of a network time
protocol (NTP) ensures consistent time across the different components and associated events and configure each
TOE component host system to ensure time synchronization across the TOE components.
2.3.5 Trusted Path
The TOE environment uses HTTPS sessions by default for remote users that protect user authentication and other
information from disclosure.
2.4 TOE Documentation
Tenable offers a series of documents that describe the installation process for the TOE as well as guidance for
subsequent use and administration of the applicable security features.
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3. Security Environment
This section summarizes the threats addressed by the TOE (often with help from its environment) and assumptions
about the intended environment of the TOE. Note that while the identified threats are mitigated by the security
functions implemented in the TOE, the overall assurance level (EAL2 augmented with ALC_FLR.2) also serves as
an indicator of whether the TOE would be suitable for a given environment.
3.1 Threats
The following are threats identified for the TOE and the IT System the TOE monitors. The TOE itself has threats
and the TOE is also responsible for addressing threats to the environment in which it resides. The assumed level of
expertise of the attacker for all the threats is unsophisticated.
3.1.1 TOE Threats
T.COMINT An unauthorized user may attempt to compromise the integrity of the data collected and produced
by the TOE by bypassing a security mechanism.
T.COMDIS An unauthorized user may attempt to disclose the data collected and produced by the TOE by
bypassing a security mechanism.
T.LOSSOF An unauthorized user may attempt to remove or destroy data collected and produced by the TOE.
T.NOHALT An unauthorized user may attempt to compromise the continuity of the System‟s collection and
analysis functions by halting execution of the TOE.
T.PRIVIL An unauthorized user may gain access to the TOE and exploit system privileges to gain access to
TOE security functions and data.
T.IMPCON An unauthorized user may inappropriately change the configuration of the TOE causing potential
intrusions to go undetected.
T.INFLUX An unauthorized user may cause malfunction of the TOE by creating an influx of data that the
TOE cannot handle.
T.FACCNT Unauthorized attempts to access TOE data or security functions may go undetected.
3.1.2 IT System Threats
The following identifies threats to the IT System that may be indicative of vulnerabilities in or misuse of IT
resources.
T.SCNCFG Improper security configuration settings may exist in the IT System the TOE monitors.
T.SCNMLC Users could execute malicious code on an IT System that the TOE monitors which causes
modification of the IT System protected data or undermines the IT System security functions.
T.SCNVUL Vulnerabilities may exist in the IT System the TOE monitors.
T.FALACT The TOE may fail to react to identified or suspected vulnerabilities or inappropriate activity.
T.FALREC The TOE may fail to recognize vulnerabilities or inappropriate activity based on IDS data received
from each data source.
T.FALASC The TOE may fail to identify vulnerabilities or inappropriate activity based on association of IDS
data received from all data sources.
T.MISUSE Unauthorized accesses and activity indicative of misuse may occur on an IT System the TOE
monitors.
T.INADVE Inadvertent activity and access may occur on an IT System the TOE monitors.
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T.MISACT Malicious activity, such as introductions of Trojan horses and viruses, may occur on an IT System
the TOE monitors.
3.2 Organizational Security Policies
An organizational security policy is a set of rules, practices and procedures imposed by an organization to address its
security needs. This section identifies the organizational security policies applicable to the Intrusion Detection
System System Protection Profile.
P.DETECT Static configuration information that might be indicative of the potential for a future intrusion or
the occurrence of a past intrusion of an IT System or events that are indicative of inappropriate
activity that may have resulted from misuse, access, or malicious activity of IT System assets must
be collected.
P.ANALYZ Analytical processes and information to derive conclusions about intrusions (past, present or
future) must be applied to IDS data and appropriate response actions taken.
P.MANAGE The TOE shall only be managed by authorized users.
P.ACCESS All data collected and produced by the TOE shall only be used for authorized purposes.
P.ACCACT Users of the TOE shall be accountable for their actions within the IDS.
P.INTGTY Data collected and produced by the TOE shall be protected from modification.
P.PROTCT The TOE shall be protected from unauthorized accesses and disruptions of TOE data and
functions.
3.3 Secure Usage Assumptions
3.3.1 Intended Usage Assumptions
A.ACCESS The TOE has access to all the IT System data it needs to perform its functions.
A.ASCOPE The TOE is appropriately scalable to the IT System the TOE monitors.
A.DYNMIC The TOE will be managed in a manner that allows it to appropriately address changes in the IT
System the TOE monitors.
3.3.2 Physical Assumptions
A.LOCATE The processing resources of the TOE will be located within controlled access facilities, which will
prevent unauthorized physical access.
A.PROTCT The TOE hardware and software critical to security policy enforcement will be protected from
unauthorized physical modification.
3.3.3 Personnel Assumptions
A.MANAGE There will be one or more competent individuals assigned to manage the TOE and its environment
and the security of the information it contains.
A.NOEVIL The authorized administrators are not careless, willfully negligent or hostile, and will follow and
abide by the instructions provided by the TOE documentation.
A.NOTRST The TOE can only be accessed by authorized users.
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4. Security Objectives
This section summarizes the security objectives for the TOE and its environment.
4.1 Security Objectives for the TOE
O.PROTCT The TOE must protect itself from unauthorized modifications and access to its functions and data.
O.IDSCAN The Scanner must collect and store static configuration information that might be indicative of the
potential for a future intrusion or the occurrence of a past intrusion of an IT System.
O.IDSENS The Sensor must collect and store information about all events that are indicative of inappropriate
activity that may have resulted from misuse, access, or malicious activity of IT System assets and
the IDS.
O.IDANLZ The Analyzer must accept data from IDS Sensors or IDS Scanners and then apply analytical
processes and information to derive conclusions about intrusions (past, present or future).
O.RESPON The TOE must respond appropriately to analytical conclusions.
O.EADMIN The TOE must include a set of functions that allow effective management of its functions and
data.
O.ACCESS The TOE must allow authorized users to access only appropriate TOE functions and data.
O.IDAUTH The TOE must be able to identify and authenticate users prior to allowing access to TOE functions
and data.
O.OFLOWS The TOE must appropriately handle potential audit and System data storage overflows.
O.AUDITS The TOE must record audit records for data accesses and use of the System functions.
O.INTEGR The TOE must ensure the integrity of all audit and System data.
O.EXPORT When any IDS component makes its data available to another IDS component, the TOE will
ensure the confidentiality of the System data.
4.2 Security Objectives for the Environment
OE.INSTAL Those responsible for the TOE must ensure that the TOE is delivered, installed, managed and
operated in a manner which is consistent with IT security.
OE.PHYCAL Those responsible for the TOE must ensure that those parts of the TOE and its environment
critical to security policy are protected from any physical attack.
OE.CREDEN Those responsible for the TOE must ensure that all access credentials are protected by the users
in a manner that is consistent with IT security.
OE.TIME The IT Environment will provide reliable timestamps to the TOE.
OE.INTROP The TOE is interoperable with the IT System it monitors.
OE.PERSON Personnel working as authorized administrators shall be carefully selected and trained for proper
operation of the system.
OE.AUDIT_PROTECTION The IT Environment will provide the capability to protect audit information.
OE.AUDIT_SORT The IT Environment will provide the capability to sort the audit information
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5. IT Security Requirements
This section defines the Security Functional Requirements (SFRs) and Security Assurance Requirements (SARs) for
the TOE and associated environment components.
The TOE also satisfies a minimum strength of function: „SOF-basic‟. The only applicable (i.e., probabilistic or
permutational) security functions are FIA_UAU.2, which is levied on the TOE.
5.1 TOE Security Functional Requirements
The following table identifies the SFRs that are candidates to be satisfied by the TOE. These are conformant to the
IDSSYPP:
Requirement Class Requirement Component
FAU: Security Audit FAU_GEN.1: Audit data generation
FAU_SAR.1: Audit review
FAU_SAR.2: Restricted audit review
FAU_SAR.3: Selectable audit review
FAU_SEL.1: Selective audit
FAU_STG.2: Guarantees of audit data availability
FAU_STG.4: Prevention of audit data loss
FIA: Identification and
Authentication
FIA_AFL.1: Authentication failure handling
FIA_ATD.1: User attribute definition
FIA_UAU.2: User authentication before any action
FIA_UID.2: User identification before any action
FMT: Security Management FMT_MOF.1: Management of security functions behavior
FMT_MTD.1: Management of TSF data
FMT_SMF.1: Specification of management functions
FMT_SMR.1: Security roles
FPT: Protection of the TSF FPT_ITT.1: Basic internal TSF data protection
FPT_STM.1 Reliable time stamps
IDS: Intrusion Detection
System
IDS_ANL.1 (EXT): Analyzer analysis
IDS_RCT.1 (EXT): Analyzer react
IDS_RDR.1 (EXT): Restricted data review
IDS_SDC.1 (EXT): System data collection
IDS_STG.1 (EXT): Guarantee of system data availability
IDS_STG.2 (EXT): Prevention of system data loss
Table 1 TOE Security Functional Components
5.1.1 FAU - Security Audit
FAU_GEN.1 - Audit Data Generation
FAU_GEN.1.1 The TSF shall be able to generate an audit record of the following auditable events: a) Start-up and
shutdown of the audit functions; b) All auditable events for the [basic] level of audit; and c)
[Access to the System and access to the TOE and System data].
FAU_GEN.1.2 The TSF shall record within each audit record at least the following information: a) Date and time
of the event, type of event, subject identity, and the outcome (success or failure) of the event; and
b) For each audit event type, based on the auditable event definitions of the functional components
included in the PP/ST, [the additional information specified in the Details column of Table 2
Auditable Events].
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Component Event Details
FAU_GEN.1 Start-up and shutdown of audit functions
FAU_GEN.1 Access to System
FAU_GEN.1 Access to the TOE and System data
Object IDS, requested
access
FAU_SAR.1 Reading of information from the audit records
FAU_SAR.2
Unsuccessful attempts to read information from the audit
records
FAU_SEL.1
All modifications to the audit configuration that occur while
the audit collection functions are operating
FIA_UAU.2 All use of the authentication mechanism User identity, location
FIA_UID.2 All use of the user identification mechanism User identity, location
FMT_MOF.1 All modifications in the behavior of the functions of the TSF
FMT_MDT.1 All modifications to the values of TSF data
FMT_SMR.1 Modifications to the group of users that are part of a role User identity
Table 2: Auditable Events
FAU_SAR.1 - Audit Review
FAU_SAR.1.1 The TSF shall provide [authorized systems administrator] with the capability to read [all audit
information] from the audit records.
FAU_SAR.1.2 The TSF shall provide the audit records in a manner suitable for the user to interpret the
information.
FAU_SAR.2 - Restricted Audit Review
FAU_SAR.2.1 The TSF shall prohibit all users read access to the audit records, except those users that have been
granted explicit read-access.
FAU_SAR.3 - Selectable Audit Review
FAU_SAR.3.1 The TSF shall provide the ability to perform [sorting] of audit data based on [date and time,
subject identity, type of event, and success or failure of related event].
FAU_SEL.1 - Selective Audit
FAU_SEL.1.1 The TSF shall be able to include or exclude auditable events from the set of audited events based
on the following attributes: a) [event type] b) [no additional attributes].
FAU_STG.2 - Guarantees of Audit Data Availability
FAU_STG.2.1 The TSF shall protect the stored audit records from unauthorized deletion.
FAU_STG.2.2 The TSF shall be able to [detect] modifications to the audit records.
FAU_STG.2.3 The TSF shall ensure that [the most recent, limited by available System data storage] audit
records will be maintained when the following conditions occur: [audit storage exhaustion].
FAU_STG.4 - Prevention of Audit Data Loss
FAU_STG.4.1 The TSF shall [prevent auditable events, except those taken by the authorised user with special
rights] and [send an alarm] if the audit trail is full.
5.1.2 FIA - Identification and Authentication
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FIA_AFL.1 - Authentication Failure Handling
FIA_AFL.1.1 The TSF shall detect when [a settable, non-zero number] of unsuccessful authentication attempts
occur related to [external IT products attempting to authenticate].
FIA_AFL.1.2 When the defined number of unsuccessful authentication attempts has been met or surpassed, the
TSF shall [prevent the offending external IT product from successfully authenticating until an
authorized administrator takes some action to make authentication possible for the external IT
product in question].
FIA_ATD.1 - User Attribute Definition
FIA_ATD.1.1 The TSF shall maintain the following list of security attributes belonging to individual users: [a)
User identity b) Authentication data c) Authorizations; and d) [Roles.]].
FIA_UAU.2 – User Authentication before any Action
FIA_UAU.2.1 The TSF shall require each user to be successfully authenticated before allowing any other TSF-
mediated actions on behalf of that user.
FIA_UID.2 – User Identification before any Action
FIA_UID.2.1 The TSF shall require each user to be successfully identified before allowing any other TSF-
mediated actions on behalf of that user.
5.1.3 FMT - Security Management
FMT_MOF.1 - Management of Security Functions Behavior
FMT_MOF.1.1 The TSF shall restrict the ability to [modify the behavior of] the functions of System data
collection, analysis and reaction to [authorized System administrators].
FMT_MTD.1 - Management of TSF Data
FMT_MTD.1.1 The TSF shall restrict the ability to [query and add] [System and audit data], and shall restrict the
ability to [query and modify] [all other TOE data] to [authorized System administrators (to
query and add system and audit data) and the authorized administrators (to query and
modify all other TOE data)].
FMT_SMF.1 Specification of Management Functions
FMT_SMF.1.1 The TSF shall be capable of performing the following security management functions:
[Management of Analyzer data, Management of Audit functions, Management of user
accounts].
FMT_SMR.1 - Security Roles
FMT_SMR.1.1 The TSF shall maintain the following roles: authorized administrator, authorized System
administrators, and [no other roles].
FMT_SMR.1.2 The TSF shall be able to associate users with roles.
Application Note: The roles in this requirement are copied from directly from the PP. The TOE realizes these roles
in the following manner. The Authorized Administrator role is a TOE environmental role and is realized by the
Systems Administrator role in the TOE. The Authorized System Administrator role is realized by four roles in the
TOE. Those roles are: SecurityCenter Administrator, Organization Head, Manager, and End User. More
information is provided in Section 6.1.3.
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5.1.4 FPT – Protection of the TSF
FPT_STM.1 Reliable time stamps
FPT_STM.1.1 The TSF shall be able to provide reliable time stamps for its own use.
FPT_ITT.1 Basic internal TSF data transfer protection
FPT_ITT.1.1 The TSF shall protect TSF data from [disclosure and modification] when it is transmitted
between separate parts of the TOE.
5.1.5 IDS – Intrusion Detection System
IDS_ANL.1 (EXT) - Analyzer analysis
IDS_ANL.1.1 The System shall perform the following analysis function(s) on all IDS data received: [signature,
statistical, integrity]; and [no other analytical functions]. (EXT)
IDS_ANL.1.2 The System shall record within each analytical result at least the following information: a. Date
and time of the result, type of result, identification of data source; and b. [location and
description]. (EXT)
Application Note: Statistical analysis involves identifying deviations from normal patterns of behavior. For
example, it may involve mean frequencies and measures of variability to identify abnormal usage. Signature
analysis involves the use of patterns corresponding to known attacks or misuses of a System. For example, patterns
of System settings and user activity can be compared against a database of known attacks. Integrity analysis
involves comparing System settings or user activity at some point in time with those of another point in time to
detect differences.
IDS_RCT.1 (EXT) - Analyzer React
IDS_RCT.1.1 The System shall send an alarm to [authorized system administrator] and take [no other action]
when an intrusion is detected. (EXT)
IDS_RDR.1 (EXT) - Restricted Data Review
IDS_RDR.1.1 The System shall provide [authorized system administrators] with the capability to read [all
data] from the System data. (EXT)
IDS_RDR.1.2 The System shall provide the System data in a manner suitable for the user to interpret the
information. (EXT)
IDS_RDR.1.3 The System shall prohibit all users read access to the System data, except those users that have
been granted explicit read-access. (EXT)
IDS_SDC.1 (EXT) - System Data Collection
IDS_SDC.1.1 The System shall be able to collect the following information from the targeted IT System
resource(s): a) [Start-up and shutdown, identification and authentication events; data accesses;
service requests; network traffic; security configuration changes; data introduction; detected
malicious code; access control configuration; service configuration; authentication
configuration; accountability policy configuration; detected known vulnerabilities]; and b) [no
other specifically defined events]. (EXT)
IDS_SDC.1.2 At a minimum, the System shall collect and record the following information: a) Date and time of
the event, type of event, subject identity, and the outcome (success or failure) of the event; and b)
The additional information specified in the Details column of the following Table 3 System
Events. (EXT).
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Event Details
Start-up and shutdown None
Identification and
authentication events
User identity, location, source address, destination
address
Data accesses
Object IDS, requested access, source address, destination
address
Service requests Specific service, source address, destination address
Network traffic Protocol, source address, destination address
Security configuration
changes
Source address, destination address
Data introduction
Object IDS, location of object, source address,
destination address
Detected malicious code Location, identification of code
Access control configuration Location, access settings
Service configuration Service identification (name or port), interface, protocols
Authentication configuration
Account names for cracked passwords, account policy
parameters
Accountability policy
configuration
Accountability policy configuration parameters
Detected known
vulnerabilities
Identification of the known vulnerability
Table 3: System Events
IDS_STG.1 (EXT) - Guarantee of System Data Availability
IDS_STG.1.1 The System shall protect the stored System data from unauthorized deletion. (EXT)
IDS_STG.1.2 The System shall protect the stored System data from modification. (EXT)
IDS_STG.1.3 The System shall ensure that [the most recent, limited by available System data storage]
System data will be maintained when the following conditions occur: [System data storage
exhaustion]. (EXT)
IDS_STG.2 (EXT) - Prevention of System data loss
IDS_STG.2.1 The System shall [prevent System data, except those taken by the authorised user with special
rights] and send an alarm if the storage capacity has been reached. (EXT)
5.2 TOE Security Assurance Requirements
The security assurance requirements for the TOE are the EAL2 augmented with ALC_FLR.2 as specified in Part 3
of the Common Criteria. No operations are applied to the assurance components.
Assurance Class Assurance Components Assurance Components
Description
Development ADV_ARC.1 Architectural Design with domain
separation and non-bypassibility
ADV_FSP.2 Security-enforcing Functional
Specification
ADV_TDS.1 Basic design
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Guidance
Documents
AGD_OPE.1 Operational user guidance
AGD_PRE.1 Preparative User guidance
Life Cycle Support ALC_CMS.2 Use of a CM system
ALC_CMS.2 Parts of the TOE CM coverage
ALC_DEL.1 Delivery Procedures
ALC_FLR.2 Flaw Reporting Procedures
Tests ATE_COV.1 Evidence of coverage
ATE_FUN.1 Functional Testing
ATE_IND.2 Independent Testing - conformance
Vulnerability
Assessment
AVA_VAN.2 Vulnerability Analysis
Table 4: EAL 2 augmented with ALC_FLR.2 Assurance Components
5.2.1 ADV -Development
5.2.1.1 ADV_ARC.1 Security architecture description
ADV_ARC.1.1D The developer shall design and implement the TOE so that the security features of the TSF cannot
be bypassed.
ADV_ARC.1.2D The developer shall design and implement the TSF so that it is able to protect itself from
tampering by untrusted active entities.
ADV_ARC.1.3D The developer shall provide a security architecture description of the TSF.
Content and presentation elements:
ADV_ARC.1.1C The security architecture description shall be at a level of detail commensurate with the description
of the SFR-enforcing abstractions described in the TOE design document.
ADV_ARC.1.2C The security architecture description shall describe the security domains maintained by the TSF
consistently with the SFRs.
ADV_ARC.1.3C The security architecture description shall describe how the TSF initialization process is secure.
ADV_ARC.1.4C The security architecture description shall demonstrate that the TSF protects itself from tampering.
ADV_ARC.1.5C The security architecture description shall demonstrate that the TSF prevents bypass of the SFR-
enforcing development functionality.
Evaluator action elements:
ADV_ARC.1.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
5.2.1.2 ADV_FSP.2 Security-enforcing functional specification
ADV_FSP.2.1D The developer shall provide a functional specification.
ADV_FSP.2.2D The developer shall provide a tracing from the functional specification to the SFRs.
Content and presentation elements:
ADV_FSP.2.1C The functional specification shall completely represent the TSF.
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ADV_FSP.2.2C The functional specification shall describe the purpose and method of use for all TSFI.
ADV_FSP.2.3C The functional specification shall identify and describe all parameters associated with each TSFI.
ADV_FSP.2.4C For each SFR-enforcing TSFI, the functional specification shall describe the SFR-enforcing actions
associated with the TSFI.
ADV_FSP.2.5C For SFR-enforcing TSFIs, the functional specification shall describe direct error messages resulting
from processing associated with the SFR-enforcing actions.
ADV_FSP.2.6C The tracing shall demonstrate that the SFRs trace to TSFIs in the functional specification.
Evaluator action elements:
ADV_FSP.2.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
ADV_FSP.2.2E The evaluator shall determine that the functional specification is an accurate and complete
instantiation of the SFRs.
5.2.1.3 ADV_TDS.1 Basic design
ADV_TDS.1.1D The developer shall provide the design of the TOE.
ADV_TDS.1.2D The developer shall provide a mapping from the TSFI of the functional specification to the lowest
level of decomposition available in the TOE design.
Content and presentation elements:
ADV_TDS.1.1C The design shall describe the structure of the TOE in terms of subsystems.
ADV_TDS.1.2C The design shall identify all subsystems of the TSF.
ADV_TDS.1.3C The design shall describe the behavior of each SFR-supporting or SFR-non-interfering TSF
subsystem in sufficient detail to determine that it is not SFR-enforcing.
ADV_TDS.1.4C The design shall summarize the SFR-enforcing behavior of the SFR-enforcing subsystems.
ADV_TDS.1.5C The design shall provide a description of the interactions among SFR-enforcing subsystems of the
TSF, and between the SFR-enforcing subsystems of the TSF and other subsystems of the TSF.
ADV_TDS.1.6C The mapping shall demonstrate that all behavior described in the TOE design is mapped to the
TSFIs that invoke it.
Evaluator action elements:
ADV_TDS.1.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
ADV_TDS.1.2E The evaluator shall determine that the design is an accurate and complete instantiation of all
security functional requirements.
5.2.2 AGD –Guidance Documents
5.2.2.1 AGD_OPE.1 Operational user guidance
AGD_OPE.1.1D The developer shall provide operational user guidance.
Content and presentation elements:
AGD_OPE.1.1C The operational user guidance shall describe, for each user role, the user-accessible functions and
privileges that should be controlled in a secure processing environment, including appropriate warnings.
AGD_OPE.1.2C The operational user guidance shall describe, for each user role, how to use the available interfaces
provided by the TOE in a secure manner.
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AGD_OPE.1.3C The operational user guidance shall describe, for each user role, the available functions and
interfaces, in particular all security parameters under the control of the user, indicating secure values as appropriate.
AGD_OPE.1.4C The operational user guidance shall, for each user role, clearly present each type of security-
relevant event relative to the user-accessible functions that need to be performed, including changing the security
characteristics of entities under the control of the TSF.
AGD_OPE.1.5C The operational user guidance shall identify all possible modes of operation of the TOE (including
operation following failure or operational error), their consequences and implications for maintaining secure
operation.
AGD_OPE.1.6C The operational user guidance shall, for each user role, describe the security measures to be
followed in order to fulfill the security objectives for the operational environment as described in the ST.
AGD_OPE.1.7C The operational user guidance shall be clear and reasonable.
Evaluator action elements:
AGD_OPE.1.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
5.2.2.2 AGD_PRE.1 Preparative procedures
AGD_PRE.1.1D The developer shall provide the TOE including its preparative procedures.
Content and presentation elements:
AGD_PRE.1.1C The preparative procedures shall describe all the steps necessary for secure acceptance of the
delivered TOE in accordance with the developer's delivery procedures.
AGD_PRE.1.2C The preparative procedures shall describe all the steps necessary for secure installation of the TOE
and for the secure preparation of the operational environment in accordance with the security objectives for the
operational environment as described in the ST.
AGD_PRE.1.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
AGD_PRE.1.2E The evaluator shall apply the preparative procedures to confirm that the TOE can be prepared
securely for operation.
5.2.3 ALC –Life Cycle Support
5.2.3.1 ALC_CMC.2 Use of a CM system
ALC_CMC.2.1D The developer shall provide the TOE and a reference for the TOE.
ALC_CMC.2.2D The developer shall provide the CM documentation.
ALC_CMC.2.3D The developer shall use a CM system.
Content and presentation elements:
ALC_CMC.2.1C The TOE shall be labeled with its unique reference.
ALC_CMC.2.2C The CM documentation shall describe the method used to uniquely identify the configuration
items.
ALC_CMC.2.3C The CM system shall uniquely identify all configuration items.
ALC_CMC.2.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
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5.2.3.2 ALC_CMS.2 Parts of the TOE CM coverage
ALC_CMS.2.1D The developer shall provide a configuration list for the TOE.
ALC_CMS.2.1C The configuration list shall include the following: the TOE itself; the evaluation evidence required
by the SARs; and the parts that comprise the TOE.
ALC_CMS.2.2C The configuration list shall uniquely identify the configuration items.
ALC_CMS.2.3C For each TSF relevant configuration item, the configuration list shall indicate the developer of the
item.
ALC_CMS.2.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
5.2.3.3 ALC_DEL.1 Delivery procedures
ALC_DEL.1.1D The developer shall document procedures for delivery of the TOE or parts of it to the consumer.
ALC_DEL.1.2D The developer shall use the delivery procedures.
ALC_DEL.1.1C The delivery documentation shall describe all procedures that are necessary to maintain security
when distributing versions of the TOE to the consumer.
ALC_DEL.1.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
5.2.3.4 ALC_FLR.2 Flaw reporting procedures
ALC_FLR.2.1D The developer shall document flaw remediation procedures addressed to TOE developers.
ALC_FLR.2.2D The developer shall establish a procedure for accepting and acting upon all reports of security flaws
and requests for corrections to those flaws.
ALC_FLR.2.3D The developer shall provide flaw remediation guidance addressed to TOE users.
ALC_FLR.2.1C The flaw remediation procedures documentation shall describe the procedures used to track all
reported security flaws in each release of the TOE.
ALC_FLR.2.2C The flaw remediation procedures shall require that a description of the nature and effect of each
security flaw be provided, as well as the status of finding a correction to that flaw.
ALC_FLR.2.3C The flaw remediation procedures shall require that corrective actions be identified for each of the
security flaws.
ALC_FLR.2.4C The flaw remediation procedures documentation shall describe the methods used to provide flaw
information, corrections and guidance on corrective actions to TOE users.
ALC_FLR.2.5C The flaw remediation procedures shall describe a means by which the developer receives from TOE
users reports and enquiries of suspected security flaws in the TOE.
ALC_FLR.2.6C The procedures for processing reported security flaws shall ensure that any reported flaws are
remediated and the remediation procedures issued to TOE users.
ALC_FLR.2.7C The procedures for processing reported security flaws shall provide safeguards that any corrections
to these security flaws do not introduce any new flaws.
ALC_FLR.2.8C The flaw remediation guidance shall describe a means by which TOE users report to the developer
any suspected security flaws in the TOE.
ALC_FLR.2.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
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5.2.4 ATE –Tests
5.2.4.1 ATE_COV.1 Evidence of coverage
ATE_COV.1.1D The developer shall provide evidence of the test coverage.
ATE_COV.1.1C The evidence of the test coverage shall show the correspondence between the tests in the test
documentation and the TSFIs in the functional specification.
ATE_COV.1.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
5.2.4.2 ATE_FUN.1 Functional testing
ATE_FUN.1.1D The developer shall test the TSF and document the results.
ATE_FUN.1.2D The developer shall provide test documentation.
ATE_FUN.1.1C The test documentation shall consist of test plans, expected test results and actual test results.
ATE_FUN.1.2C The test plans shall identify the tests to be performed and describe the scenarios for performing
each test. These scenarios shall include any ordering dependencies on the results of other tests.
ATE_FUN.1.3C The expected test results shall show the anticipated outputs from a successful execution of the tests.
ATE_FUN.1.4C The actual test results shall be consistent with the expected test results.
ATE_FUN.1.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
5.2.4.3 ATE_IND.2 Independent testing – sample
ATE_IND.2.1D The developer shall provide the TOE for testing.
ATE_IND.2.1C The TOE shall be suitable for testing.
ATE_IND.2.2C The developer shall provide an equivalent set of resources to those that were used in the developer's
functional testing of the TSF.
ATE_IND.2.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
ATE_IND.2.2E The evaluator shall execute a sample of tests in the test documentation to verify the developer test
results.
ATE_IND.2.3E The evaluator shall test a subset of the TSF to confirm that the TSF operates as specified.
5.2.5 AVA –Vulnerability Assessment
5.2.5.1 AVA_VAN.2 Vulnerability analysis
AVA_VAN.2.1D The developer shall provide the TOE for testing.
AVA_VAN.2.1C The TOE shall be suitable for testing.
AVA_VAN.2.1E The evaluator shall confirm that the information provided meets all requirements for content and
presentation of evidence.
AVA_VAN.2.2E The evaluator shall perform a search of public domain sources to identify potential vulnerabilities
in the TOE.
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AVA_VAN.2.3E The evaluator shall perform an independent vulnerability analysis of the TOE using the guidance
documentation, functional specification, TOE design and security architecture description to identify potential
vulnerabilities in the TOE.
AVA_VAN.2.4E The evaluator shall conduct penetration testing, based on the identified potential vulnerabilities, to
determine that the TOE is resistant to attacks performed by an attacker possessing basic attack potential.
6. TOE Summary Specification
This chapter describes the security functions and associated assurance measures.
6.1 TOE Security Functions
6.1.1 Security Audit
The TOE generates audit records for at least the basic level of audit, including the following events.
 Start-up and shutdown the SC4 component. If the SC4 component is enabled, then auditing is turned on and
cannot be turned off.
 Access to the system by TOE users
 Access to the TOE and system data by other system components
 Successful and unsuccessful attempts to read from the audit trail
 Successful and unsuccessful attempts to launch scans
 Modifications to the audit configuration
 Successful and unsuccessful attempts at user identification and authentication
 Modifications to the TSF configuration and data
 Modifications to the TOE users‟ role assignments
Each audit record contains at least the following information: date and time of the event, event type, subject identity,
and event success or failure.
The SC4 provides a web-based interface for viewing audit records. The admin user is the only role authorized access
the audit records. There is no configuration option to enable another user to view the audit logs or to turn off the
audit function. The audit functionality is built-in to the application and there are no options available to disable it.
The web interface allows the admin user to search the audit date based on keyword or keyword combination
searches. The current month‟s audit file is searched by default but other files can be specified.
TOE security audit records are stored in flat files that can grow to use all the space in the file system. A new file is
started at the beginning of each month. These files are small compared to the IDS data and are only constrained in
size by the size of their disk partition. The vendor provides guidance to administrators and users on how to configure
audit storage to prevent it from becoming exhausted. Note that the TOE can be configured to monitor the disk usage
on each component and issue an alarm via the SC4 and also send an e-mail to a configured user (Organization Head
by default) should the available disk space drop below a limit (the default is 15%) defined by the administrator when
configuring the function. The authorized administrator configures and manages the audit storage, but the authorized
system administrator (the SCA) is the only role that the TOE authorizes to access the audit records.
The Security Audit function satisfies the following security functional requirements:
 FAU_GEN.1: Audit data generation
 FAU_SAR.1: Audit review
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 FAU_SAR.2: Restricted audit review
 FAU_SAR.3: Selectable audit review
 FAU_SEL.1: Selective audit
 FAU_STG.2: Audit data availability
 FAU_STG.4: Prevention of audit data loss
6.1.2 Identification and Authentication
The SC4 TOE component provides an HTTPS-based GUI login interface. TOE users are required to login to the
SC4 TOE component with a unique name and password before access to the TOE is granted. The TOE maintains
user identities, authentication data, authorization information and role association information for each user. Users
must be successfully identified and authenticated prior to accessing any reports.
The SecurityCenter Administrator can configure the TOE to lock a specific account after a configurable number of
consecutive unsuccessful login attempts occur. It is up to users to contact a SecurityCenter Administrator to request
that a locked account be unlocked.
When using the 3DT and xTool clients, users must still authenticate successfully to the SC4. The 3DT client is
simply an application that makes visualization more pleasant for the administrator. The 3DT application will pass
authentication credentials to the SC4 to perform authentication before any TOE information can be displayed to the
end user. The xTool application will pass authentication credentials to the SC4 to perform authentication before any
scan result or repository query information can be displayed to the end user.
The Identification and Authentication function satisfies the following security functional requirements:
 FIA_AFL.1: Authentication failure handling
 FIA_ATD.1: User attribute definition
 FIA_UAU.2: Timing of authentication
 FIA_UID.2: Timing of identification
6.1.3 Security Management
The IDSSYPP defines two roles: Authorized Administrator and Authorized System Administrator. The Authorized
Administrator role is a TOE environmental role and is realized by the Systems Administrator role in the TOE. The
Authorized System Administrator role is realized by four roles in the TOE. Those roles are: SecurityCenter
Administrator, Organization Head, Manager, and End User. The term “TOE users” will be used when referring to all
four of the TOE roles, since only the four administrative roles are allowed access by the TOE. Otherwise, each role
will be identified specifically. The TOE restricts the ability to manage functions related to audit and system data to
SecurityCenter Administrators. They are able to query and add system and audit data; and query and modify all
other TOE data. Scanning, sensing and analyzing tasks are restricted to Organization Heads, Managers and End
Users, who can modify the behavior of system data collection, analysis and reaction. The environment supports the
Authorized Administrator role. Authorized Administrators manage the operating systems, and install and configure
the TOE.
Organization Heads, Managers and End Users operate the IDS system on specific parts of the network domain space
called an Organization. An Organization is made up of one or more managers who perform actions for the
Organization. The Managers are expected to work together for an Organization. Organization Heads and Managers
administer an Organization network and are able to initiate Organization analyzer IDS audit functions, access IDS
audit data and manage user accounts. Only Organization Heads are able to add new IDS sources. End Users
administer a specific sub-network within an Organization network. Depending on the size of the Organization, some
or all of these roles may be assigned to one individual.
The Organization Head is the first account created for a TOE Organization. If the Organization Head account is
deleted, the Organization is also deleted, even if other Manager accounts are active at the time.
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The TOE maintains a directory structure in the host file system to hold data for specific Organizations.
Subdirectories can be created to further subdivide Organization data according to sub-networks. The SecurityCenter
Administrator creates this structure in the course of configuring Organizations and gives access to the
Organization‟s Organization Head, who may then create other Managers and End Users. Organization Heads and
Managers can restrict the access that End Users have within the Organization structure and thus restrict them to
operating the IDS on specific subsets of the Organization network.
The TOE offers access by Organization Heads, Managers and End Users via these directories, according to the
scope of their authority. Organization Heads and Managers can access Organization directories. End Users can
access only specific subdirectories within an Organization directory. This access is determined by the TOE. When
an Organization Head account is deleted, the corresponding Organization directory is also deleted.
User access is restricted by the role to which the user is assigned and the assets to which the user has been granted
access. All SC4 functions are controlled by asset lists. Individual SecurityCenter users are assigned one or more
asset lists. These lists can be either static or dynamic. Users who have the ability to scan can only scan hosts in their
asset lists. Similarly, users can only see vulnerability, compliance, intrusion detection, and normalized logs for
systems within their asset groups. The role indicates what functionality (i.e., which menu options) the TOE presents
to each user. The assets are the machines for which the user can launch IDS scans and access IDS audit records.
The Authorized Administrator environmental role is implemented by the underlying operating system, where it is
called System Administrator or Administrator or Root. It has full access to the underlying operating system and, by
implication, the entire TOE.
The Security Management function satisfies the following security functional requirements:

 FMT_MOF.1: Management of security functions behavior
 FMT_MTD.1: Management of TSF data
 FMT_SMF.1: Specification of management functions
6.1.4 FMT_SMR.1: Security roles
The TOE uses the SSH and SSL capabilities of its environment when communicating among its distributed parts to
protect transferred data from disclosure and modification. SSH and SCP (over SSH) is used between the SC4 and
the LCE. In all other instances, SSL is used. The cryptographic keys necessary to support this use of SSH and SSL
are created or installed during the installation or administration of the operating systems that run under the TOE
components. TOE administrator guidance documents include advice on administering the SSH and SSL mechanisms
in the environment.
Note that SSH and SSL are fully implemented within the hosts of the TOE applications. However, the guidance
documents refer to configuring SSH and SSL for use by the components, this is done within the host operating
systems and not via TOE functions. While there is an expectation that the environment will provide SSH and SSL
services that can be used by the TOE, the TOE has no specific requirements about the implementation of SSH and
SSL (e.g., its algorithm). As such, this ST does not define specific cryptographic requirements for itself nor for its
environment.
The TOE instantiates itself as a process provided by the underlying operating system. The TOE protects its files
using features provided by the underlying operating system. Specifically, it ensures that the security properties of
those objects do not allow access by other operating system processes. This serves to both protect the TOE itself as
well as to ensure that any attempts to access the data collected by the TOE must be made through the TOE.
Furthermore, the TOE has been carefully designed to offer well-defined interfaces that ensure that access to
protected resources is subject to the applicable TOE security policies.
The TOE uses capabilities of its environment to provide a source of reliable time stamps, which the TOE uses in its
audit function. The system administrator needs to be aware that use of Network Time Protocol (NTP) ensures
consistent time across the different TOE components and associated events and such functionality must be enabled
in order to ensure the reliability of this function.
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 FPT_ITT.1: Basic internal TSF data transfer protection
 FPT_STM.1: Reliable time stamps
6.1.5 Intrusion Detection System
The TOE collects and records network traffic data for use by the scanning, sensing and analyzing functions with the
SC4. The following event types are collected:
 Identification and authentication
 Data accesses
 Service Requests
 Network Traffic
 Security Configuration Changes
 Data Introduction
 Detected Malicious Code
 Access Control Configuration
 Service Configuration
 Authentication Configuration
 Accountability Policy Configuration
For each event, the TOE records at least the following information: date and time of the event, type of event, subject
identity, and the outcome (success or failure) of the event.
The SecurityCenter Administrator can specify the types of events that will be audited by configuring the various
PVS and Nessus scanners deployed in the monitored system. The TOE comes with several pre-configured audit
configuration files that were derived from NSA and other guidelines for the configuration of Unix and Windows
systems.
The TOE performs analysis on all signature, statistical and integrity data. Signature analysis involves identifying
deviations from normal patterns of behavior (e.g., it may use mean frequencies and measures of variability to
identify abnormal usage). Statistical analysis involves identifying patterns of usage that correspond to known attacks
or misuses of the system (e.g., patters of system settings and user activity can be compared against a database of
known attacks). Integrity analysis involves comparing system settings or user activity at some point in time with that
at another point in time to detect (possibly unauthorized) differences. When analysis identifies an anomaly, the TOE
records an analytical result that contains at least the date and time of the result, type of result, identification of data
source, location and description.
Reports are generated using a web-based interface to SC4 that provides access to the LCE, allowing users to
examine analytical conclusions and the information used to reach those conclusions in an intuitive way.
TOE users access reports via a web browser. The SecurityCenter Administrator controls access to the reports based
on userid and role.
When an intrusion is detected, the TOE can generate alarms and notify anyone, using a notification mechanism,
such as e-mail, that is configured by the SecurityCenter Administrator.
LCE stores events into one or more silos (there can be up to 255). Each silo consists of an index file and a data file.
When a silo is filled (determined by the maximum silo size), the next silo is written to. When the last silo is filled,
the first silo is overwritten. The silo mechanism and the large maximum disk space supported by the TOE allows the
system to be configured with enough storage so that filled silos can be copied to long term storage and returned to
use before all of the disk space is consumed and before any IDS data are overwritten. However, if the system is not
provided with adequate silo storage space or silo maintenance is neglected, IDS data can be lost. With sufficient
neglect, the maximum number of lost IDS data is unbounded. In order to mitigate overflow of storage, the LCE and
SC4 components both support filtering of inputs based on IP address.
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Each silo has a maximum file size specified in MB or GB. The maximum file size for a silo is 4 GB. With 255
potential silos, that is approximately 1.5 terabytes of potential IDS data storage. In practice, the vendor recommends
that the LCE servers be tuned to handle up to 250 million events. Assuming roughly 300 bytes per record, this will
require approximately 75 GBs. However, some organizations will have shorter or longer messages.
In the evaluated configuration, the TOE is configured to periodically download updated signature files and plugins
from Tenable servers over the Internet. Connection is made to the download server using HTTPS which serves to
authenticate the server to the TOE. The TOE authenticates itself to the server by providing a Nessus Plugin
Subscription Activation Code that is distributed with the product and entered during product installation. The PVS
component does encrypt the plugins. Nessus does not encrypt the plugins it distributes; rather it has a two-tiered
approach: regular and 'trusted'. Trusted plugins must be signed by Tenable, or a user can create / sign a plugin as
well. The signature tells Nessus that the plugin is trusted and allows it to perform more operations at a lower level to
the system.
The environment is responsible to restrict access to IDS data via its interfaces so that in effect the TOE controls
access to that data.
The Intrusion Detection System function satisfies the following security functional requirements:
 IDS_ANL.1 (EXT): Analyzer analysis
 IDS_RCT.1 (EXT): Analyzer react
 IDS_RDR.1 (EXT): Restricted data review
 IDS_SDC.1 (EXT): System data collection
 IDS_STG.1 (EXT): Guarantee of system data availability
 IDS_STG.2 (EXT): Prevention of system data loss
Section 2.1 (TOE Description) and 2.2 (TOE Architecture) of the ST contain more detailed information about the
specific IDS capabilities of the TOE.
7. Protection Profile Claims
The TOE conforms to the US Government Intrusion Detection System System Protection Profile (IDSSYPP),
Version 1.7, July 25, 2007.
This Security Target includes all of the Security Functional and Security Assurance Requirements from the PP.
This Security Target includes all of the assumptions and threats statements described in the PP, verbatim. None were
added.
This Security Target includes all of the Security Objectives from the PP, verbatim. However, the environment
objective for physical protection of the TOE has been extended to address components in the environment also
critical to the secure operation of the TOE.
Section 5 of this Security Target specifically identifies each of the operations that have been performed on
requirements drawn from the PP. Note that operations already performed in the PP have not been identified in this
Security Target.
The following SFRs from the PP have not been included in this ST: FPT_ITA.1, FPT_ITC.1, and FPT_ITI.1. They
were dropped because the TOE has no communications with external IT products, making these SFRs unnecessary.
Additionally, FPT_ITT.1 should be included when the TOE is a distributed TOE. The IDS system described herein
is a distributed TOE so FPT_ITT.1 has been included.
FIA_UID.1 and FIA_UAU.1 in the IDSSYPP were upgraded to FIA_UID.2 and FIA_UAU.2 in the ST to accurately
reflect what the TOE does. They are both hierarchical to the corresponding SFRs in the PP.
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FMT_SMF.1 was added to capture the security function management capabilities of the TOE.
The Tenable product suite provides the specified level of audit to satisfy the IDSSYPP. Operational environment
objectives are included in this Security Target to cover any objectives not directly addressable by the TOE.
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8. Rationale
This section provides the rationale for the selection of the IT security requirements, objectives, assumptions, and
threats. In particular, it shows that the IT security requirements are suitable to meet the security objectives, which in
turn are shown to be suitable to cover all aspects of the TOE security environment. The rationale addresses the
following areas:
 Security Objectives;
 Security Functional Requirements;
 Security Assurance Requirements;
 Strength of Functions;
 Requirement Dependencies;
 Extended Requirements Rationale
 TOE Summary Specification; and,
 PP Claims.
8.1 Security Objectives Rationale
This section provides a rationale for the existence of each assumption, threat, and policy statement that compose the
Intrusion Detection System System Protection Profile. The following discussion provides detailed evidence of
coverage for each assumption, threat, and policy.
8.1.1 Complete Coverage – Environmental Assumptions
This section shows coverage of the Non-IT security objectives by the environmental assumptions. The following
table shows this assumption to objective mapping.
OE.INSTAL
OE.PHYCAL
OE.CREDEN
OE.PERSON
OE.INTROP
Intended usage
assumptions
A.ACCESS X
A.ASCOPE X
A.DYNMIC X X
Physical assumptions A.LOCATE X
A.PROTCT X
Personnel
assumptions
A.MANAGE X
A.NOEVIL X X X
A.NOTRST X X
8.1.1.1 A.ACCESS
The TOE has access to all the IT System data it needs to perform its functions.
This Assumption is satisfied by ensuring that:
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 OE.INTROP: The OE.INTROP objective ensures the TOE has the needed access.
8.1.1.2 A.ASCOPE
The TOE is appropriately scalable to the IT System the TOE monitors.
This Assumption is satisfied by ensuring that:
 OE.INTROP: The OE.INTROP objective ensures the TOE has the necessary interactions with the IT
System it monitors.
8.1.1.3 A.DYNMIC
The TOE will be managed in a manner that allows it to appropriately address changes in the IT System the
TOE monitors.
This Assumption is satisfied by ensuring that:
 OE.INTROP: The OE.INTROP objective ensures the TOE has the proper access to the IT System.
 OE.PERSON: The OE.PERSON objective ensures that the TOE will be managed appropriately.
8.1.1.4 A.LOCATE
The processing resources of the TOE will be located within controlled access facilities, which will prevent
unauthorized physical access.
This Assumption is satisfied by ensuring that:
 OE.PHYCAL: The OE.PHYCAL provides for the physical protection of the TOE.
8.1.1.5 A.PROTCT
The TOE software critical to security policy enforcement will be protected from unauthorized physical
modification.
This Assumption is satisfied by ensuring that:
 OE.PHYCAL: The OE.PHYCAL provides for the physical protection of the TOE hardware and software.
8.1.1.6 A.MANAGE
There will be one or more competent individuals assigned to manage the TOE and the security of the
information it contains.
This Assumption is satisfied by ensuring that:
 OE.PERSON: The OE.PERSON objective ensures all authorized administrators are qualified and trained to
manage the TOE.
8.1.1.7 A.NOEVIL
The authorized administrators are not careless, willfully negligent or hostile, and will follow and abide by
the instructions provided by the TOE documentation.
This Assumption is satisfied by ensuring that:
 OE.INSTAL: The OE.INSTAL objective ensures that the TOE is properly installed and operated.
 OE.PHYCAL: The OE.PHYCAL objective provides for physical protection of the TOE by authorized
administrators.
 OE.CREDEN: The OE.CREDEN objective supports this assumption by requiring protection of all
authentication data.
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8.1.1.8 A.NOTRST
The TOE can only be accessed by authorized users.
This Assumption is satisfied by ensuring that:
 OE.PHYCAL: The OE.PHYCAL objective provides for physical protection of the TOE to protect against
unauthorized access.
 OE.CREDEN: The OE.CREDEN objective supports this assumption by requiring protection of all
authentication data.
8.1.2 Complete Coverage – Organizational Security Policies
This section shows that all organizational security policies are completely covered by the TOE security objectives
and that each objective counters or addresses at least one policy.
O.PROTCT
O.IDSCAN
O.IDSENS
O.IDANLZ
O.EADMIN
O.ACCESS
O.IDAUTH
O.OFLOWS
O.AUDITS
O.INTEGR
OE.INSTAL
OE.PHYCAL
OE.CREDEN
OE.PERSON
OE.TIME
OE.AUDIT_SORT
OE.AUDIT_PROTECTION
P.DETECT X X X X
P.ANALYZ X
P.MANAGE X X X X X X X
P.ACCESS X X X X
P.ACCACT X X X X
P.INTGTY X
P.PROTCT X X
8.1.2.1 P.DETECT
Static configuration information that might be indicative of the potential for a future intrusion or the occurrence
of a past intrusion of an IT System or events that are indicative of inappropriate activity that may have resulted
from misuse, access, or malicious activity of IT System assets must be collected.
This Policy is satisfied by ensuring that:
 O.AUDITS: the required system audit data is collected.
 O.IDSENS: the required sensor data is collected.
 O.IDSCAN: the required scanner data is collected.
 OE.TIME: The IT Environment will provide reliable time stamp to the TOE. Time stamps associated with
an audit record must be reliable.
8.1.2.2 P.ANALYZ
Analytical processes and information to derive conclusions about intrusions (past, present or future) must be
applied to IDS data and appropriate response actions taken.
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This Policy is satisfied by ensuring that:
 O.IDANLZ: The O.IDANLZ objective requires analytical processes be applied to data collected from
Sensors and Scanners.
8.1.2.3 P.MANAGE
The TOE shall only be managed by authorized users.
This Policy is satisfied by ensuring that:
 O.PROTCT: The O.PROTCT objective addresses this policy by providing TOE self-protection.
 OE.PERSON: The OE.PERSON objective ensures competent administrators will manage the TOE.
 O.EADMIN: The O.EADMIN objective ensures there is a set of functions for administrators to use.
 OE.INSTAL: The OE.INSTAL objective supports the OE.PERSON objective by ensuring administrator
follow all provided documentation and maintain the security policy.
 O.IDAUTH: The O.IDAUTH objective provides for authentication of users prior to any TOE function
accesses.
 O.ACCESS: The O.ACCESS objective builds upon the O.IDAUTH objective by only permitting
authorized users to access TOE functions.
 OE.CREDEN: The OE.CREDEN objective requires administrators to protect all authentication data.
8.1.2.4 P.ACCESS
All data collected and produced by the TOE shall only be used for authorized purposes.
This Policy is satisfied by ensuring that:
 O.IDAUTH: The O.IDAUTH objective provides for authentication of users prior to any TOE function
accesses.
 O.ACCESS: The O.ACCESS objective builds upon the O.IDAUTH objective by only permitting
authorized users to access TOE functions.
 O.PROTCT: The O.PROTCT objective addresses this policy by providing TOE self-protection.
 OE.AUDIT_PROTECTION: The TOE is required to protect the audit data from deletion as well as
guarantee the availability of the audit data in the event of storage exhaustion, failure or attack .
8.1.2.5 P.ACCACT
Users of the TOE shall be accountable for their actions within the IDS.
This Policy is satisfied by ensuring that:
 O.AUDITS: The O.AUDITS objective implements this policy by requiring auditing of all data accesses and
use of TOE functions.
 O.IDAUTH: The O.IDAUTH objective supports this objective by ensuring each user is uniquely identified
and authenticated.
 OE.TIME: The IT Environment will provide reliable time stamp to the TOE. Time stamps associated with
an audit record must be reliable .
 OE.AUDIT_SORT: The IT environment must provide the ability to review and manage the audit trail of
the System to include sorting the audit data.
8.1.2.6 P.INTGTY
Data collected and produced by the TOE shall be protected from modification.
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This Policy is satisfied by ensuring that:
 O.INTEGR: The O.INTEGR objective ensures the protection of data from modification.
8.1.2.7 P. PROTCT
The TOE shall be protected from unauthorized accesses and disruptions of TOE data and functions.
This Policy is satisfied by ensuring that:
 O.OFLOWS: The O.OFLOWS objective counters this policy by requiring the TOE handle disruptions.
 OE.PHYCAL: The OE.PHYCAL objective protects the TOE from unauthorized physical modifications.
8.1.3 Complete Coverage – Threats
This section shows that all threats are completely covered by the TOE security objectives and that each objective
counters or addresses at least one threat.
O.PROTCT
O.IDSCAN
O.IDSENS
O.IDANLZ
O.RESPON
O.EADMIN
O.ACCESS
O.IDAUTH
O.OFLOWS
O.AUDITS
O.INTEGR
O.EXPORT
OE.INSTAL
T.COMINT X X X X
T.COMDIS X X X X
T.LOSSOF X X X X
T.NOHALT X X X X X
T.PRIVIL X X X
T.IMPCON X X X X
T.INFLUX X
T.FACCNT X
T.SCNCFG X
T.SCNMLC X
T.SCNVUL X
T.FALACT X
T.FALREC X
T.FALASC X
T.MISUSE X
T.INADVE X
T.MISACT X
8.1.3.1 T.COMINT
An unauthorized user may attempt to compromise the integrity of the data collected and produced by the TOE
by bypassing a security mechanism.
This Threat is satisfied by ensuring that:
 O.IDAUTH: The O.IDAUTH objective provides for authentication of users prior to any TOE data access.
 O.ACCESS: The O.ACCESS objective builds upon the O.IDAUTH objective by only permitting
authorized users to access TOE data.
 O.INTEGR: The O.INTEGR objective ensures no TOE data will be modified.
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 O.PROTCT: The O.PROTCT objective addresses this threat by providing TOE self-protection.
8.1.3.2 T.COMDIS
An unauthorized user may attempt to disclose the data collected and produced by the TOE by bypassing a
security mechanism.
This Threat is satisfied by ensuring that:
 O.IDAUTH: The O.IDAUTH objective provides for authentication of users prior to any TOE data access.
 O.ACCESS: The O.ACCESS objective builds upon the O.IDAUTH objective by only permitting
authorized users to access TOE data.
 O.EXPORT: The O.EXPORT objective ensures that confidentiality of TOE data will be maintained.
 O.PROTCT: The O.PROTCT objective addresses this threat by providing TOE self-protection.
8.1.3.3 T.LOSSOF
An unauthorized user may attempt to remove or destroy data collected and produced by the TOE.
This Threat is satisfied by ensuring that:
 O.IDAUTH: The O.IDAUTH objective provides for authentication of users prior to any TOE data access.
 O.ACCESS: The O.ACCESS objective builds upon the O.IDAUTH objective by only permitting
authorized users to access TOE data.
 O.INTEGR: The O.INTEGR objective ensures no TOE data will be deleted.
 O.PROTCT: The O.PROTCT objective addresses this threat by providing TOE self-protection.
8.1.3.4 T.NOHALT
An unauthorized user may attempt to compromise the continuity of the System’s collection and analysis
functions by halting execution of the TOE.
This Threat is satisfied by ensuring that:
 O.IDAUTH: The O.IDAUTH objective provides for authentication of users prior to any TOE function
accesses.
 O.ACCESS: The O.ACCESS objective builds upon the O.IDAUTH objective by only permitting
authorized users to access TOE functions.
 O.IDSCAN, O.IDSENS, and O.IDANLZ: The O.IDSCAN, O.IDSENS, and O.IDANLZ objectives address
this threat by requiring the TOE to collect and analyze System data, which includes attempts to halt the
TOE.
8.1.3.5 T.PRIVIL
An unauthorized user may gain access to the TOE and exploit system privileges to gain access to TOE security
functions and data.
This Threat is satisfied by ensuring that:
 O.IDAUTH: The O.IDAUTH objective provides for authentication of users prior to any TOE function
accesses.
 O.ACCESS: The O.ACCESS objective builds upon the O.IDAUTH objective by only permitting
authorized users to access TOE functions.
 O.PROTCT: The O.PROTCT objective addresses this threat by providing TOE self-protection.
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8.1.3.6 T.IMPCON
An unauthorized user may inappropriately change the configuration of the TOE causing potential intrusions to
go undetected.
This Threat is satisfied by ensuring that:
 O.EADMIN: The O.EADMIN objective ensures the TOE has all the necessary administrator functions to
manage the product.
 O.IDAUTH: The O.IDAUTH objective provides for authentication of users prior to any TOE function
accesses.
 O.ACCESS: The O.ACCESS objective builds upon the O.IDAUTH objective by only permitting
authorized users to access TOE functions.
 OE.INSTAL: The OE.INSTAL objective states the authorized administrators will configure the TOE
properly.
8.1.3.7 T.INFLUX
An unauthorized user may cause malfunction of the TOE by creating an influx of data that the TOE cannot
handle.
This Threat is satisfied by ensuring that:
 O.OFLOWS: The O.OFLOWS objective counters this threat by requiring the TOE handle data storage
overflows.
8.1.3.8 T.FACCNT
Unauthorized attempts to access TOE data or security functions may go undetected.
This Threat is satisfied by ensuring that:
 O.AUDITS: The O.AUDITS objective counters this threat by requiring the TOE to audit attempts for data
accesses and use of TOE functions.
8.1.3.9 T.SCNCFG
Improper security configuration settings may exist in the IT System the TOE monitors.
This Threat is satisfied by ensuring that:
 O.IDSCAN: The O.IDSCAN objective counters this threat by requiring a TOE, that contains a Scanner,
collect and store static configuration information that might be indicative of a configuration setting change.
The ST will state whether this threat must be addressed by a Scanner.
8.1.3.10 T.SCNMLC
Users could execute malicious code on an IT System that the TOE monitors which causes modification of the IT
System protected data or undermines the IT System security functions.
This Threat is satisfied by ensuring that:
 O.IDSCAN: The O.IDSCAN objective counters this threat by requiring a TOE, that contains a Scanner,
collect and store static configuration information that might be indicative of malicious code. The ST will
state whether this threat must be addressed by a Scanner.
8.1.3.11 T.SCNVUL
Vulnerabilities may exist in the IT System the TOE monitors.
This Threat is satisfied by ensuring that:
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 O.IDSCAN: The O.IDSCAN objective counters this threat by requiring a TOE, that contains a Scanner,
collect and store static configuration information that might be indicative of a vulnerability. The ST will
state whether this threat must be addressed by a Scanner.
8.1.3.12 T.FALACT
The TOE may fail to react to identified or suspected vulnerabilities or inappropriate activity.
This Threat is satisfied by ensuring that:
 O.RESPON: The O.RESPON objective ensures the TOE reacts to analytical conclusions about suspected
vulnerabilities or inappropriate activity.
8.1.3.13 T.FALREC
The TOE may fail to recognize vulnerabilities or inappropriate activity based on IDS data received from each
data source.
This Threat is satisfied by ensuring that:
 O.IDANLZ: The O.IDANLZ objective provides the function that the TOE will recognize vulnerabilities or
inappropriate activity from a data source.
8.1.3.14 T.FALASC
The TOE may fail to identify vulnerabilities or inappropriate activity based on association of IDS data received
from all data sources.
This Threat is satisfied by ensuring that:
 O. IDANLZ: The O. IDANLZ objective provides the function that the TOE will recognize vulnerabilities
or inappropriate activity from multiple data sources.
8.1.3.15 T.MISUSE
Unauthorized accesses and activity indicative of misuse may occur on an IT System the TOE monitors.
This Threat is satisfied by ensuring that:
 O.IDSENS: the TOE, that contains a Sensor, collects sensor data.
 O.AUDIT: the TOE, that contains a Sensor, collects audit data.
8.1.3.16 T.INADVE
Inadvertent activity and access may occur on an IT System the TOE monitors.
This Threat is satisfied by ensuring that:
 O.IDSENS: the TOE, that contains a Sensor, collects sensor data.
 O.AUDIT: the TOE, that contains a Sensor, collects audit data.
8.1.3.17 T.MISACT
Malicious activity, such as introductions of Trojan horses and viruses, may occur on an IT System the TOE
monitors.
This Threat is satisfied by ensuring that:
 O.IDSENS: the TOE, that contains a Sensor, collects sensor data.
 O.AUDIT: the TOE, that contains a Sensor, collects audit data.
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8.2 Security Requirements Rationale
This section provides evidence supporting the internal consistency and completeness of the components
(requirements) in the Security Target. Note that Table 5 indicates the requirements that effectively satisfy the
individual objectives.
8.2.1 Security Functional Requirements Rationale
All Security Functional Requirements (SFR) identified in this Security Target are fully addressed in this section and
each SFR is mapped to the objective(s) that it is intended to satisfy.
O.PROTCT
O.IDSCAN
O.IDSENS
O.IDANLZ
O.RESPON
O.EADMIN
O.ACCESS
O.IDAUTH
O.OFLOWS
O.AUDITS
O.INTEGR
O.EXPORT
OE.TIME
OE.AUDIT_SORT
OE.AUDIT_PROTECTION
FAU_GEN.1 X
FAU_SAR.1 X
FAU_SAR.2 X X
FAU_SAR.3 X X
FAU_SEL.1 X X
FAU_STG.2 X X X X X X
FAU_STG.4 X X
FIA_UAU.2 X X
FIA_ATD.1 X
FIA_UID.2 X X
FMT_MOF.1 X X X
FMT_MTD.1 X X X X
FMT_SMR.1 X
FMT_SMF.1 X X X X
FPT_ITT.1 X X X
ADV_ARC.1 X X X X X
FPT_STM.1 X X
IDS_ANL.1 (EXT) X
IDS_RCT.1 (EXT) X
IDS_RDR.1 (EXT) X X X
IDS_SDC.1 (EXT) X X
IDS_STG.1 (EXT) X X X X X
IDS_STG.2 (EXT) X
Table 5: Objective to Requirement Correspondence
8.2.1.1 O.PROTCT
The TOE must protect itself from unauthorized modifications and access to its functions and data.
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This TOE Security Objective is satisfied by ensuring that:
 The TOE is required to protect the audit data from deletion as well as guarantee the availability of the audit
data in the event of storage exhaustion, failure or attack [FAU_STG.2].
 The System is required to protect the System data from any modification and unauthorized deletion, as well
as guarantee the availability of the data in the event of storage exhaustion, failure or attack [IDS_STG.1].
 The TOE is required to provide the ability to restrict managing the behavior of functions of the TOE to
authorized users of the TOE [FMT_MOF.1].
 Only authorized administrators of the System may query and add System and audit data, and authorized
administrators of the TOE may query and modify all other TOE data [FMT_MTD.1].
 Communications among distributed TOE components is protected from disclosure and modification.
[FPT_ITT.1]
 The TOE must ensure that all functions are invoked and succeed before each function may proceed
[ADV_ARC.1].
 The TSF must be protected from interference that would prevent it from performing its functions
[ADV_ARC.1].
8.2.1.2 O.IDSCAN
The Scanner must collect and store static configuration information that might be indicative of the potential for
a future intrusion or the occurrence of a past intrusion of an IT System.
This TOE Security Objective is satisfied by ensuring that:
 A System containing a Scanner is required to collect and store static configuration information of an IT
System. The type of configuration information collected must be defined in the ST [IDS_SDC.1].
8.2.1.3 O.IDSENS
The Sensor must collect and store information about all events that are indicative of inappropriate activity that
may have resulted from misuse, access, or malicious activity of IT System assets and the IDS.
This TOE Security Objective is satisfied by ensuring that:
 A System containing a Sensor is required to collect events indicative of inappropriate activity that may
have resulted from misuse, access, or malicious activity of IT System assets of an IT System. These events
must be defined in the ST [IDS_SDC.1].
8.2.1.4 O.IDANLZ
The Analyzer must accept data from IDS Sensors or IDS Scanners and then apply analytical processes and
information to derive conclusions about intrusions (past, present or future).
This TOE Security Objective is satisfied by ensuring that:
 The Analyzer is required to perform intrusion analysis and generate conclusions [IDS_ANL.1].
8.2.1.5 O.RESPON
The TOE must respond appropriately to analytical conclusions.
This TOE Security Objective is satisfied by ensuring that:
 The TOE is required to respond accordingly in the event an intrusion is detected [IDS_RCT.1].
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8.2.1.6 O.EADMIN
The TOE must include a set of functions that allow effective management of its functions and data.
This TOE Security Objective is satisfied by ensuring that:
 The TOE must provide the ability to review and manage the audit trail of the System [FAU_SAR.1,
FAU_SEL.1].
 The System must provide the ability for authorized administrators to view all System data collected and
produced [IDS_RDR.1].
 The TOE must ensure that all functions are invoked and succeed before each function may proceed
[ADV_ARC.1].
 The TSF must be protected from interference that would prevent it from performing its functions
[ADV_ARC.1].
8.2.1.7 O.ACCESS
The TOE must allow authorized users to access only appropriate TOE functions and data.
This TOE Security Objective is satisfied by ensuring that:
 The TOE is required to restrict the review of audit data to those granted with explicit read-access
[FAU_SAR.2].
 The System is required to restrict the review of System data to those granted with explicit read-access
[IDS_RDR.1].
 The TOE is required to protect the audit data from deletion as well as guarantee the availability of the audit
data in the event of storage exhaustion, failure or attack [FAU_STG.2].
 The System is required to protect the System data from any modification and unauthorized deletion
[IDS_STG.1].
 Users authorized to access the TOE are defined using an identification and authentication process
[FIA_UID.2, FIA_UAU.2].
 The TOE is required to provide the ability to restrict managing the behavior of functions of the TOE to
authorized users of the TOE [FMT_MOF.1].
 Only authorized administrators of the System may query and add System and audit data, and authorized
administrators of the TOE may query and modify all other TOE data [FMT_MTD.1].
 A System provides functions to allow the management of audit functions and user accounts.
[FMT_SMF.1].
8.2.1.8 O.IDAUTH
The TOE must be able to identify and authenticate users prior to allowing access to TOE functions and data.
This TOE Security Objective is satisfied by ensuring that:
 The TOE is required to restrict the review of audit data to those granted with explicit read-access
[FAU_SAR.2].
 The System is required to restrict the review of System data to those granted with explicit read-access
[IDS_RDR.1].
 The TOE is required to protect the stored audit records from unauthorized deletion [FAU_STG.2].
 The System is required to protect the System data from any modification and unauthorized deletion, as well
as guarantee the availability of the data in the event of storage exhaustion, failure or attack [IDS_STG.1].
 Security attributes of subjects use to enforce the authentication policy of the TOE must be defined
[FIA_ATD.1].
 Users authorized to access the TOE are defined using an identification and authentication process
[FIA_UID.2, FIA_UAU.2].
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 The TOE is required to provide the ability to restrict managing the behavior of functions of the TOE to
authorized users of the TOE [FMT_MOF.1].
 Only authorized administrators of the System may query and add System and audit data, and authorized
administrators of the TOE may query and modify all other TOE data [FMT_MTD.1].
 A System provides functions to allow the management of audit functions and user accounts.
[FMT_SMF.1].
 The TOE must be able to recognize the different administrative and user roles that exist for the TOE
[FMT_SMR.1].
 The TOE must ensure that all functions are invoked and succeed before each function may proceed
[ADV_ARC.1].
 The TSF must be protected from interference that would prevent it from performing its functions
[ADV_ARC.1].
8.2.1.9 O.OFLOWS
The TOE must appropriately handle potential audit and System data storage overflows.
This TOE Security Objective is satisfied by ensuring that:
 The TOE is required to protect the audit data from deletion as well as guarantee the availability of the audit
data in the event of storage exhaustion, failure or attack [FAU_STG.2].
 The TOE must prevent the loss of audit data in the event that its audit trail is full [FAU_STG.4].
 The System is required to protect the System data from any modification and unauthorized deletion, as well
as guarantee the availability of the data in the event of storage exhaustion, failure or attack [IDS_STG.1].
 The System must prevent the loss of audit data in the event the audit trail is full [IDS_STG.2].
8.2.1.10 O.AUDITS
The TOE must record audit records for data accesses and use of the System functions.
This TOE Security Objective is satisfied by ensuring that:
 Security-relevant events must be defined and auditable for the TOE [FAU_GEN.1].
 The TOE must provide the capability to select which security-relevant events to audit [FAU.SEL.1].
 The TOE must prevent the loss of collected data in the event its audit trail is full [FAU_STG.4].
 A System provides functions to allow the management of audit functions and user accounts.
[FMT_SMF.1].
 The TOE must ensure that all functions are invoked and succeed before each function may proceed
[ADV_ARC.1].
 The TSF must be protected form interference that would prevent it from performing its functions
[ADV_ARC.1].
 Time stamps associated with an audit record must be reliable [FPT_STM.1].
8.2.1.11 O.INTEGR
The TOE must ensure the integrity of all audit and System data.
This TOE Security Objective is satisfied by ensuring that:
 The TOE is required to protect the audit data from deletion as well as guarantee the availability of the audit
data in the event of storage exhaustion, failure or attack [FAU_STG.2].
 The System is required to protect the System data from any modification and unauthorized deletion
[IDS_STG.1].
 Only authorized administrators of the System may query or add audit and System data [FMT_MTD.1].
 A System provides functions to allow the management of audit functions and user accounts.
[FMT_SMF.1].
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 Communications among distributed TOE components is protected from disclosure and modification.
[FPT_ITT.1].
 The TOE must ensure that all functions to protect the data are not bypassed [ADV_ARC.1].
 The TSF must be protected from interference that would prevent it from performing its functions
[ADV_ARC.1].
8.2.1.12 O.EXPORT
When any IDS component makes its data available to another IDS component, the TOE will ensure the
confidentiality of the System data.
This TOE Security Objective is satisfied by ensuring that:
 Data is protected when transmitted between separate parts of the TOE. [FPT_ITT.1].
8.2.1.13 OE.TIME
The IT Environment will provide reliable timestamps to the TOE.
This Environment Security Objective is satisfied by ensuring that:
 Time stamps associated with an audit record must be reliable [FPT_STM.1].
8.2.1.14 OE.AUDIT_SORT
The IT Environment will provide the capability to protect audit information.
This Environment Security Objective is satisfied by ensuring that:
 The IT environment must provide the ability to review and manage the audit trail of the System to include
sorting the audit data [FAU_SAR.3].
8.2.1.15 OE.AUDIT_PROTECTION
The IT Environment will provide the capability to protect System (i.e., IDS) information.
This Environment Security Objective is satisfied by ensuring that:
,
 The TOE is required to protect the audit data from deletion as well as guarantee the availability of the audit
data in the event of storage exhaustion, failure or attack [FAU_STG.2].
8.3 Security Assurance Requirements Rationale
The selected security assurance level is EAL2 augmented with ALC_FLR.2.
EAL2 was chosen to provide a low to moderate level of assurance that is consistent with good commercial practices.
As such, minimal additional tasks are placed upon the vendor assuming the vendor follows reasonable software
engineering practices and can provide support to the evaluation for design and testing efforts. The chosen assurance
level is appropriate with the threats defined for the environment. While the System may monitor a hostile
environment, it is expected to be in a non-hostile position and embedded in or protected by other products designed
to address threats that correspond with the intended environment. At EAL2, the System will have incurred a search
for obvious flaws to support its introduction into the non-hostile environment.
The base assurance level was augmented with ALC_FLR.2. because clear and complete documentation of all modes
of operation of the TOE and the assumptions and requirements for the TOE environment allows the user to deploy
the TOE securely and in a manner that best achieves the goals of the organization.
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8.4 Requirement Dependency Rationale
The EAL2 assurance package is defined in the CC to be internally consistent. The dependencies of the EAL2
augmentations specified in this ST (ALC_FLR.2) are met as follows: ALC_FLR.2 has no dependencies per the
active PP.
The SFRs included in the ST have all been adopted from the PP, with the following exceptions:
FPT_ITT.1 has been added and has no dependencies.
FMT_SMF.1 has been added and has no dependencies.
FPT_ITC.1 has been removed but does not serve to fulfill any dependencies of any other SFRs.
FPT_ITA.1 has been removed but does not serve to fulfill any dependencies of any other SFRs.
FPT_ITI.1 has been removed but does not serve to fulfill any dependencies of any other SFRs.
Other than the exceptions listed above, the rationale listed in the PP is applicable to this ST.
8.5 Extended Requirements Rationale
The IDS class of explicitly stated security functional requirements captures the TOE‟s basic functionality for
collecting system data (IDS_SDC.1 (EXT)), analyzing that data for evidence of intrusions (IDS_ANL.1 (EXT)),
reacting and reporting on the analysis results (IDS_RCT.1 (EXT)), and protecting the availability (IDS_STG.1
(EXT)), integrity and confidentiality (IDS_STG.2 (EXT)) of the results. It captures the unique nature of IDS data
and provides requirements for collecting, reviewing and managing the data.
The CC contains no security functional requirements that fully describe these requirements, although the audit
family of the CC (FAU) was used as a model.
These explicit requirements are specified in the IDSSYPP, to which this ST claims conformance.
These requirements have no dependencies since the stated requirements embody all the necessary security functions.
8.6 TOE Summary Specification Rationale
Each subsection in Section 6, the TOE Summary Specification, describes a security function of the TOE. Each
description is followed with rationale that indicates which requirements are satisfied by aspects of the corresponding
security function, demonstrating that the set of security functions work together to satisfy all of the security
functions and assurance requirements. Furthermore, all of the security functions are necessary in order for the TSF
to provide the required security functionality.
Security
audit
Identification
and
authentication
Security
management
Protection
of
the
TSF
Intrusion
detection
system
FAU_GEN.1 X
FAU_SAR.1 X
FAU_SAR.2 X
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FAU_SAR.3 X
FAU_SEL.1 X
FAU_STG.2 X
FAU_STG.4 X
FIA_AFL.1 X
FIA_ATD.1 X
FIA_UAU.2 X
FIA_UID.2 X
FMT_MOF.1 X
FMT_MTD.1 X
FMT_SMF.1 X
FMT_SMR.1 X
FPT_ITT.1 X
FPT_STM.1 X
IDS_ANL.1 (EXT) X
IDS_RCT.1 (EXT) X
IDS_RDR.1 (EXT) X
IDS_SDC.1 (EXT) X
IDS_STG.1 (EXT) X
IDS_STG.2 (EXT) X
Table 6: Security Functions vs. Requirements Mapping