DRQ-04-01 – Certificato Common Criteria – v1.2 del 17/10/2024 Pag. 1 di 37
Agenzia per la Cybersicurezza Nazionale
Schema nazionale per la valutazione e la certificazione della sicurezza nel settore della tecnologia
dell'informazione (DPCM del 30 ottobre 2003 - G.U. n. 93 del 27 aprile 2004)
Il prodotto identificato in questo certificato è risultato conforme ai requisiti
ISO/IEC 15408 Common Criteria (CC) ve.3.1 rel. 5
Certificato n.
(Certificate No.)
07/2025
Rapporto di Certificazione
(Certification Report)
OCSI/CERT/ATS/07/2024/RC, v 1.0.
Decorrenza
(Date of 1st
Issue)
29 settembre 2025
Nome e Versione del Prodotto
(Product Name and Version)
IBM z/OS Version 2 Release 5
Sviluppatore
(Developer)
IBM Corporation
Tipo di Prodotto
(Type of Product)
Sistema Operativo
Livello di Garanzia
(Assurance Level)
EAL4+ (ALC_FLR.3) conforme a CC Parte 3
Conformità a PP
(PP Conformance)
Nessuna
Funzionalità di sicurezza
(Conformance of Functionality)
TDS specifico per il prodotto, conforme CC Parte 2 estesa
Riconoscimento CCRA per componenti
fino a EAL2 e solo ALC_FLR
(CCRA recognition for components up to
EAL2 and ALC_FLR only)
Riconoscimento SOGIS MRA
per componenti fino a EAL4
(SOGIS MRA recognition
for components up to EAL4)
Roma, 29 settembre 2025
Il Capo Servizio
Certificazione e Vigilanza
(A. Billet)
[ORIGINAL SIGNED]
Il prodotto IT (Information Technology) identificato nel presente certificato è stato valutato
presso un LVS (Laboratorio per la Valutazione della Sicurezza) accreditato e
abilitato/approvato utilizzando Metodologia Comune per la Valutazione di Sicurezza della
tecnologia dell’Informazione versione 3.1 revisione 5 per la conformità ai Criteri Comuni
per la Valutazione di Sicurezza della Tecnologia dell’Informazione versione 3.1 revisione
5. Questo certificato si applica solo alla versione e al rilascio specifici del prodotto nella sua
configurazione valutata e unitamente al Rapporto di certificazione completo. La valutazione
è stata condotta in conformità alle disposizioni dello Schema nazionale per la valutazione e
la certificazione della sicurezza nel settore della tecnologia dell'informazione (DPCM del
30 ottobre 2003 - G.U. n. 93 del 27 aprile 2004) e le conclusioni dell’LVS nel Rapporto di
Fine Valutazione sono coerenti con le evidenze addotte. Il presente Certificato non
costituisce un sostegno o promozione del prodotto IT da parte della Agenzia per la
Cybersicurezza Nazionale o di qualsiasi altra organizzazione che riconosca o dia effetto a
questo certificato, e nessuna garanzia del prodotto IT, da parte della Agenzia per la
Cybersicurezza Nazionale o di qualsiasi altra organizzazione che riconosce o dà effetto a
questo certificato, è espressa o implicita.
The IT product identified in this certificate has been evaluated at an accredited and
licensed/approved evaluation facility using Common Methodology for Information Technology
Security Evaluation version 3.1 release 5 for conformance to Common Criteria for Information
Technology Security Evaluation version 3.1 release 5. This certificate applies only to the specific
version and release of the product in its evaluated configuration and in conjunction with the complete
Certification report. The evaluation has been conducted in accordance with the provisions of the
National scheme for the evaluation and certification of the security in the sector of information
technology (Prime Ministerial Decree of 30 October 2003 - Official Journal no. 93 of 27 April 2004)
and the conclusions of the evaluation facility in the evaluation technical report are consistent with
the evidence adduced. This certificate is not an endorsement of the IT product by Agenzia per la
Cybersicurezza Nazionale or by any other organisation that recognises or gives effect to this
certificate, and no warranty of the IT product, by Agenzia per la Cybersicurezza Nazionale or by
any other organisation that recognises or gives effect to this certificate, is either expressed or
implied.
Page 1 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
Agenzia per la Cybersicurezza Nazionale
Servizio Certificazione e Vigilanza
Certification Report
IBM z/OS version 2 Release 5
OCSI/CERT/ATS/07/2024/RC
Version 1.0
29 September 2025
Page 2 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
Courtesy translation
Disclaimer: This English language translation is provided for informational purposes only. It is not
intended to substitute the official document and has no legal value. The original Italian language
version of the document is the only approved and official version.
Page 3 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
1 Document revisions
Version Author Information Date
1.0 OCSI First issue 29/09/2025
Page 4 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
2 Table of contents
1 Document revisions ....................................................................................................................3
2 Table of contents ........................................................................................................................4
3 Acronyms....................................................................................................................................6
3.1 National scheme.................................................................................................................6
3.2 CC and CEM......................................................................................................................6
3.3 Other acronyms..................................................................................................................6
4 References ..................................................................................................................................9
4.1 Normative references and national Scheme documents ....................................................9
4.2 Technical documents .........................................................................................................9
5 Recognition of the certificate ...................................................................................................11
5.1 European recognition of CC certificates (SOGIS-MRA)................................................11
5.2 International recognition of CC certificates (CCRA)......................................................11
6 Statement of certification..........................................................................................................12
7 Summary of the evaluation.......................................................................................................13
7.1 Introduction......................................................................................................................13
7.2 Executive summary .........................................................................................................13
7.3 Evaluated product ............................................................................................................13
7.3.1 TOE architecture ........................................................................................................14
7.3.2 TOE security features.................................................................................................14
7.4 Documentation.................................................................................................................18
7.5 Protection Profile conformance claims............................................................................18
7.6 Functional and assurance requirements...........................................................................18
7.7 Evaluation conduct ..........................................................................................................18
7.8 General considerations about the certification validity ...................................................19
8 Evaluation outcome..................................................................................................................20
8.1 Evaluation results.............................................................................................................20
8.2 Recommendations............................................................................................................21
9 Annex A – Guidelines for the secure usage of the product......................................................22
9.1 TOE delivery ...................................................................................................................22
9.1.1 Scope of TOE supply .................................................................................................22
9.1.2 Delivery procedure.....................................................................................................25
9.2 Installation, configuration and secure usage of the TOE.................................................26
10 Annex B – Evaluated configuration .........................................................................................31
Page 5 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
10.1 TOE operational environment .........................................................................................31
11 Annex C – Test activity............................................................................................................32
11.1 Test configuration............................................................................................................32
11.2 Functional tests performed by the Developer..................................................................32
11.2.1 Test approach .............................................................................................................32
11.2.2 Test Coverage.............................................................................................................33
11.2.3 Test results..................................................................................................................33
11.3 Functional and independent tests performed by the Evaluators ......................................34
11.3.1 Test approach .............................................................................................................34
11.3.2 Test result ...................................................................................................................34
11.4 Vulnerability analysis and penetration tests ....................................................................34
Page 6 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
3 Acronyms
3.1 National scheme
DPCM Decreto del Presidente del Consiglio dei Ministri
LGP Linea Guida Provvisoria
LVS Laboratorio per la Valutazione della Sicurezza
NIS Nota Informativa dello Schema
OCSI Organismo di Certificazione della Sicurezza Informatica
3.2 CC and CEM
CC Common Criteria
CCRA Common Criteria Recognition Arrangement
CEM Common Evaluation Methodology
cPP collaborative Protection Profile
EAL Evaluation Assurance Level
ETR Evaluation Technical Report
PP Protection Profile
SAR Security Assurance Requirement
SFP Security Function Policy
SFR Security Functional Requirement
SOGIS-MRA Senior Officials Group Information Systems Security – Mutual Recognition
Agreement
ST Security Target
TOE Target of Evaluation
TSF TOE Security Functionality
TSFI TSF Interface
3.3 Other acronyms
AES Advanced Encryption Standard
APAR Authorized Program Analysis Report
Page 7 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
APF Authorized Program Facility
APPC/MVS Advanced Program-to-Program Communication / Multiple Virtual Storage
ASLR Address Space Layout Randomization
BCP Base Control Program
BDT Bulk Data Transfer
BERD Background Environment Random Driver
BSC Binary Synchronous Communication
CA Certificate Authority
CBPDO Custom-Built Product Delivery Option
CM Configuration Management
COMSEC COMmunication SECurity
CPACF Central Processor Assist for Cryptographic Function
CVE Common Vulnerabilities and Exposures
DAC Discretionary Access Control
DCAS Digital Certificate Access Server
DES Data Encryption Standard
DFS Distributed File Service
DFSMS Data Facility Storage Management Subsystem
DPCM Decreto del Presidente del Consiglio dei Ministri
ECC Elliptic Curve Cryptography
FMID Function Modification Identifier
FTP File Transfer Protocol
FTPS FTP Secure
FVT Functional Verification Testing
ICSF Integrated Cryptographic Service Facility
IKE Internet Key Exchange
IPD Integrated Product Development
Page 8 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
IPL Initial Program Load
JES Job Entry System
LDAP Lightweight Directory Access Protocol
NJE Network Job Entry
OCSP Online Certificate Status Protocol
PR/SM Processor Resources/System Manager
PTF Program Temporary Fix
RACF Resource Access Control Facility
RRSF RACF Remote Sharing Facility
RSA Rivest-Shamir-Adleman
SHA Secure Hash Algorithm
SMB Server Message Block
SMF System Management Facilities
SNA Systems Network Architecture
SREL Subsystem Release
SSH Secure SHell
SSL Secure Socket Layer
SVC Supervisor Call
SVT System Verification Tests
TDES Triple DES
TLS Transport Layer Security
VICOM Virtual COMputer
XBM Execution Batch Monitor
z/OSMF zOS Management Facility
Page 9 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
4 References
4.1 Normative references and national Scheme documents
[CC1] CCMB-2017-04-001, “Common Criteria for Information Technology Security
Evaluation, Part 1 – Introduction and general model”, Version 3.1, Revision 5, April
2017
[CC2] CCMB-2017-04-002, “Common Criteria for Information Technology Security
Evaluation, Part 2 – Security functional components”, Version 3.1, Revision 5, April
2017
[CC3] CCMB-2017-04-003, “Common Criteria for Information Technology Security
Evaluation, Part 3 – Security assurance components”, Version 3.1, Revision 5, April
2017
[CCRA] Arrangement on the Recognition of Common Criteria Certificates In the field of
Information Technology Security, July 2014
[CEM] CCMB-2017-04-004, “Common Methodology for Information Technology Security
Evaluation – Evaluation methodology”, Version 3.1, Revision 5, April 2017
[LGP1] Schema nazionale per la valutazione e certificazione della sicurezza di sistemi e
prodotti nel settore della tecnologia dell’informazione - Descrizione Generale dello
Schema Nazionale - Linee Guida Provvisorie - parte 1 – LGP1 versione 1.0, dicembre
2004
[LGP2] Schema nazionale per la valutazione e certificazione della sicurezza di sistemi e
prodotti nel settore della tecnologia dell’informazione - Accreditamento degli LVS e
abilitazione degli Assistenti - Linee Guida Provvisorie - parte 2 – LGP2 versione 1.0,
dicembre 2004
[LGP3] Schema nazionale per la valutazione e certificazione della sicurezza di sistemi e
prodotti nel settore della tecnologia dell’informazione - Procedure di valutazione -
Linee Guida Provvisorie - parte 3 – LGP3, versione 1.0, dicembre 2004
[NIS1] Organismo di certificazione della sicurezza informatica, Nota Informativa dello
Schema N. 1/23 – Modifiche alla LGP1, versione 1.1, 21 agosto 2023
[NIS2] Organismo di certificazione della sicurezza informatica, Nota Informativa dello
Schema N. 2/23 – Modifiche alla LGP2, versione 1.1, 21 agosto 2023
[NIS3] Organismo di certificazione della sicurezza informatica, Nota Informativa dello
Schema N. 3/23 – Modifiche alla LGP3, versione 1.1, 21 agosto 2023
[NIS5] Organismo di certificazione della sicurezza informatica, Nota Informativa dello
Schema N. 3/23 - Condizioni per lo svolgimento di test da remoto in valutazioni
Common Criteria, versione 1.1, 21 agosto 2023
[SOGIS] Mutual Recognition Agreement of Information Technology Security Evaluation
Certificates, Version 3, January 2010
4.2 Technical documents
[CR] Certificate n.1/22, IBM z/OS version 2 release 4, 13 January 2022.
Page 10 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
[ETRv2] Final Evaluation Technical Report IBM z/OS Version 2 Release 5, OCSI-CERT-
ATS-07-2024_ETR_250630, atsec information security s.r.l., v.2, 30 June 2025.
[ETRv3] Final Evaluation Technical Report IBM z/OS Version 2 Release 5, OCSI-CERT-
ATS-07-2024_ETR_250821, atsec information security s.r.l., v.3.0, 21 August
2025.
[MLSGUIDE] z/OS V2.5 Planning for Multilevel Security and the Common Criteria, code
GA32-0891-50, 16 January 2025.
[ST] Security Target for z/OS v.2.27, 27 June 2025.
[SIA] Security Impact Analysis: z/OS V2R4 to z/OS V2R5 v.1.2, 18 marzo 2024.
[ZARCH] z/Architecture Principles of Operation, February 2008.
Page 11 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
5 Recognition of the certificate
5.1 European recognition of CC certificates (SOGIS-MRA)
The European SOGIS-Mutual Recognition Agreement (SOGIS-MRA, version 3 [SOGIS]) became
effective in April 2010 and provides mutual recognition of certificates based on the Common Criteria
(CC) Evaluation Assurance Level up to and including EAL4 for all IT -Products. A higher recognition
level for evaluations beyond EAL4 is provided for IT -Products related to specific Technical Domains
only.
The current list of signatory nations and of technical domains for which the higher recognition applies
and other details can be found on https://www.sogis.eu/.
The SOGIS-MRA logo printed on the certificate indicates that it is recognised under the terms of this
agreement by signatory nations.
This certificate is recognised under SOGIS-MRA for all claimed assurance components up to EAL4.
5.2 International recognition of CC certificates (CCRA)
The current version of the international arrangement on the mutual recognition of certificates based
on the CC (Common Criteria Recognition Arrangement, [CCRA] was ratified on 8 September 2014.
It covers CC certificates compliant with collaborative Protection Profiles (cPP), up to and including
EAL4, or certificates based on assurance components up to and including EAL2, with the possible
augmentation of components from Flaw Remediation family (ALC_FLR).
The current list of signatory nations and of collaborative Protection Profiles (cPP) and other details
can be found on https://www.commoncriteriaportal.org/.
The CCRA logo printed on the certificate indicates that it is recognised under the terms of this
agreement by signatory nations.
This certificate is recognised under CCRA for all claimed assurance components up to EAL2 and
ALC_FLR only.
Page 12 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
6 Statement of certification
The Target of Evaluation (TOE) is the product named “IBM z/OS version 2 Release 5”, developed
by International Business Machines (IBM) Corporation.
z/OS is a general-purpose, multi-user, multi-tasking operating system for enterprise computing
systems. Multiple users can use z/OS simultaneously to perform a variety of functions that require
controlled, shared access to the information stored on the system.
The evaluation has been conducted in accordance with the requirements established by the Italian
Scheme for the evaluation and certification of security systems and products in the field of
information technology and expressed in the Provisional Guidelines [LGP1, LGP2, LGP3] and
Scheme Information Notes [NIS1, NIS2, NIS3, NIS5]. The Scheme is operated by the Italian
Certification Body “Organismo di Certificazione della Sicurezza Informatica (OCSI)”, established
by the Prime Minister Decree (DPCM) of 30 October 2003 (O.J. n.98 of 27 April 2004).
This Certification Report was issued at the conclusion of the re-certification of an earlier version of
the same TOE (IBM z/OS Version 2 Release 4), already certified by OCSI (Certificate no. 1/22 of
January 13, 2022 [CR]).
Due to some changes made to the product by the Developer IBM Corp., it was deemed necessary to
undertake a re-certification of the TOE [SIA]. The new version of the TOE includes new
functionalities in components already included in the already certified TOE version 2 release 4,
functionalities in new components developed for the TOE version 2 release 5 and functionalities in
components developed for TOE version 2 release 4 but made available to z/OS customers after the
conclusion of the previous certification process (and thus not considered in the Certificate no. 1/22).
Note that the changes have also led to the revision of the Security Target [ST]. Customers of the
previous version of the TOE are therefore advised to take also into account the new ST.
While the considerations and recommendations already expressed for the previous certified version
of the TOE remain largely valid, for ease of reading this Certification Report has been rewritten in its
entirety to constitute an autonomous document associated with the new TOE “IBM z/OS Version 2
Release 5”.
The objective of the evaluation is to provide assurance that the product complies with the security
requirements specified in the associated Security Target [ST]; the potential consumers of the product
should review also the Security Target, in addition to the present Certification Report, in order to gain
a complete understanding of the security problem addressed. The evaluation activities have been
carried out in accordance with the Common Criteria Part 3 [CC3] and the Common Evaluation
Methodology [CEM].
The TOE resulted compliant with the requirements of Part 3 of the CC version 3.1 Revision 5 for the
assurance level EAL4, augmented with ALC_FLR.3, according to the information provided in the
Security Target [ST] and in the configuration shown in “Annex B – Evaluated configuration” of this
Certification Report.
The publication of the Certification Report is the confirmation that the evaluation process has been
conducted in accordance with the requirements of the evaluation criteria Common Criteria - ISO/IEC
15408 ([CC1], [CC2], [CC3]) and the procedures indicated by the Common Criteria Recognition
Arrangement [CCRA] and that no exploitable vulnerability was found. However, the Certification
Body with such a document does not express any kind of support or promotion of the TOE.
Page 13 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
7 Summary of the evaluation
7.1 Introduction
This Certification Report states the outcome of the Common Criteria evaluation of the product named
“IBM z/OS Version 2 Release 5” to provide assurance to the potential consumers that TOE security
features comply with its security requirements.
In addition to the present Certification Report, the potential consumers of the product should also
review the Security Target [ST], specifying the functional and assurance requirements and the
intended operational environment.
7.2 Executive summary
TOE name IBM z/OS Version 2 Release 5
Security Target Security Target for z/OS version 2.27, 27 June 2025 [ST]
Evaluation Assurance Level EAL4 augmented with ALC_FLR.3
Developer IBM Corporation
Sponsor IBM Corporation
LVS atsec information security s.r.l.
CC version 3.1 Rev. 5
PP conformance claim No conformance claimed
Evaluation starting date April 30, 2024
Evaluation ending date June 30, 2025
The certification results apply only to the version of the product shown in this Certification Report
and only if the operational environment assumptions described in the Security Target [ST] are
fulfilled and, in the configuration, shown in “Annex B – Evaluated configuration” of this Certification
Report.
7.3 Evaluated product
This section summarizes the main functional and security requirements of the TOE. For a detailed
description refer to the Security Target [ST].
The Target of Evaluation (TOE) is the z/OS operating system with the software components as
described in Table 2, sect. 9.1.1.
Multiple users can use z/OS simultaneously to perform functions that require controlled, shared
access to the information stored on the system. The TOE Security Functional Requirements are
implemented by the following TOE Security Functions: identification and authentication,
discretionary access control, auditing, security management, cryptographic support, Communications
Security, TSF protection, confidentiality protection of datasets.
For a more detailed description of the TOE, please refer to sect. 1.5 (“TOE description”) of the
Page 14 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
Security Target [ST].
7.3.1 TOE architecture
The TOE is one instance of z/OS running on an abstract machine as the sole operating system and
exercising full control over this abstract machine. This abstract machine, the most of which not being
part of the TOE as described below, can be provided by one of the following:
• a logical partition provided by a certified version of Processor Resources/ System Manager
(PR/SM) running on an IBM z System processor (System z16)
• a certified version of IBM z/VM executing in a logical partition provided by PR/SM on the
above-mentioned z System processors.
The underlying abstract machine itself is not part of the TOE, rather, it belongs to the TOE
environment. In particular this applies to the following functions:
• privileged processor instructions (only available to programs running in the processor's
supervisor state);
• semi-privileged instructions (only available to programs running in an execution environment
that is established and authorized by the TSF);
• memory protection mechanisms, while in operation, of all address spaces, as well as the data
and tasks contained therein.
Cryptographic functions implemented by the Crypto Express 8 coprocessors are used to perform
cryptographic operations as well to handle cryptographic keys. It should be noted that a cryptographic
coprocessor is required to operate the TOE in its evaluated configuration. The same applies to the
z/Architecture's feature 3863 providing CPACF functions, these are required to operate the TOE as
well.
Most of the TOE security functions (TSF) are provided by the z/OS operating system Base Control
Program (BCP) and the Resource Access Control Facility (RACF), a z/OS component that is used by
different services as the central instance for identification and authentication and for access control
decisions. z/OS provides management functions that allow configuring the TOE security functions.
Some elements have been included in the TOE that do not provide security functions. These elements
run in authorized mode, so they could compromise the TOE if they do not behave properly. Because
these elements are essential for the operation of many customer environments, the inclusion of these
elements subjects them to the process of scrutiny during the evaluation and ensures that they may be
used by customers without affecting the TOE's security status.
7.3.2 TOE security features
The primary security features of the TOE are:
• Identification and authentication.
• Discretionary access control.
• Auditing.
• Object reuse
• Security management.
• Cryptographic support.
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• Communication security.
• TSF protection.
• Confidentiality protection of datasets.
They are supported by domain separation and reference mediation, which ensure that the features are
always invoked and cannot be bypassed.
7.3.2.1 Identification and Authentication
z/OS provides identification and authentication of users by the means of:
• an alphanumeric RACF user ID and a system-encrypted password or (for applications that
support it) password phrase;
• an alphanumeric RACF user ID and a PassTicket, which is a cryptographically-generated
password substitute encompassing the user ID, the requested application name, and the current
date/time;
• an SSH key that is configured to be trusted by the user and that is presented to the SSH server
during the authentication process.
In the evaluated configuration, all human users are assigned a unique user ID. This user ID supports
individual accountability. The TOE security functions authenticate the claimed identity of the user
by verifying the password/phrase (or other mechanism, as listed above) before allowing the user to
perform any actions that require TSF mediation, other than actions that aid an authorized user in
gaining access to the TOE.
The password quality can be tailored to the installation's policies using various parameters. When
creating users, administrators are required to choose an initial password and optionally a password
phrase, that must usually be changed by the user during the initial logon that uses the password/phrase.
Administrators may configure the number of unsuccessful authentication attempts that can be met
before the account is disabled.
7.3.2.2 Discretionary Access Control (DAC)
z/OS supports access controls that are capable of enforcing access limitations on individual users and
data objects; RACF makes access control decisions based on the user’s identity, security attributes,
group authorities, and the access authority specified with respect to the resource profile.
7.3.2.3 Auditing
The TOE provides an auditing capability that allows generating audit records for security-critical
events. RACF provides a number of logging and reporting functions that allow resource owners and
auditors to identify users who attempt to access resources. Audit records are collected by the System
Management Facilities (SMF) into an audit trail, which is protected from unauthorized modification
or deletion by the DAC mechanisms.
The system can be configured to halt on exhaustion of audit trail space to prevent audit data loss while
operators are warned when audit trail space consumption reaches a predefined threshold.
RACF always generates audit records for such events as unauthorized attempts to access the system
or changes to the status of the RACF database. The security administrator, auditors, and other users
with appropriate authorization can configure which additional optional security events are to be
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logged. RACF provides SMF records for all RACF-protected resources (either “traditional” or z/OS
UNIX-based).
7.3.2.4 Object re-use functionality
Reuse of protected objects and of storage is handled by various hardware and software controls, and
by administrative practices.
All memory content of non-shared page frames is cleared before making it accessible to other address
spaces or data spaces. All resources allocated to UNIX objects are cleared before reuse. Other data
pools are under strict TOE control and cannot be accessed directly by normal users.
7.3.2.5 Security management
z/OS provides a set of commands and options to adequately manage the TOE's security functions.
Additionally, the TOE provides the capability of managing users, groups of users as well as general
resource profiles.
7.3.2.6 Cryptographic support
The TOE provides cryptographic functions by the Integrated Cryptographic Services Facility (ICSF)
subsystem. ICSF uses cryptographic hardware provided by the operational environment to provide
and support cryptographic functions.
The TOE implements TLS Version 1.2 and Version 1.3 as well SSH version 2 for communication
and remote access.
The TOE uses cryptographic support provided by the processor by means of the CPU's CPACF
function.
All key material used for cryptographic functions described in this Security Target when in volatile
memory are in memory that is assigned to and is accessible by the TSF only.
7.3.2.7 Communication security
z/OS provides different means of secure communication between systems sharing the same security
policy, including trusted communication channels for TCP/IP connections. The confidentiality and
integrity of network connections are assured by Transport Layer Security (TLS) encrypted
communication for TCP/IP connections (Version 1.2 and Version 1.3). z/OS also supports the SSH
v2 protocol and the ssh-daemon provided services of ssh (secure shell), scp (secure copy), and sftp
(secure ftp).
In addition to the TLS connection, z/OS also supports the IP Security (IPSec) protocol with Internet
Key Exchange (IKE) as the key exchange method. This is an additional way to set up a trusted channel
to another trusted IT product for IP-based connections. z/OS also provides centralized policy
management for IPSec policies across multiple z/OS systems in the network. It also provides
centralized management for digital certificates, message signing, and message verification for IPSec
across multiple z/OS systems in the network.
7.3.2.8 TSF Protection
TSF protection is based on several protection mechanisms that are provided by the underlying abstract
machine: privileged processor instructions, semi-privileged instructions and (while in operation)
memory protection mechanisms.
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The TOE's address space management ensures that programs running in problem state cannot access
protected memory or resources that belong to other address spaces.
Tools are provided in the TOE environment to allow authorized administrators to check the correct
operation of the underlying abstract machine.
The TOE also provides the following mechanisms to protect its TSF:
• authorized program facility (APF),
• address space layout randomization (ASLR),
• stack buffer overflow protection,
• verification of integrity of the IPL process,
• trusted software updates using digital signatures.
7.3.2.9 Confidentiality protection of data sets
With z/OS confidentiality protection of data sets, users can encrypt data at rest without requiring
application changes. z/OS data set encryption through RACF commands and policies allows the
administrator to identify the data sets or groups of data sets that require encryption.
With data set encryption, the administrator is able to protect viewing the data in the clear. This is
based on access to the key label that is associated with the data set and used by the access methods to
encrypt and decrypt the data.
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7.4 Documentation
The guidance documentation specified in “Annex A – Guidelines for the secure usage of the product”
is delivered to the customer together with the product.
The guidance documentation contains all the information for secure initialization, configuration, and
secure usage of the TOE in accordance with the requirements of the Security Target [ST].
Customers should also follow the recommendations for the secure usage of the TOE contained in
section 8.2 of this report.
7.5 Protection Profile conformance claims
The Security Target [ST] does not claim conformance to any Protection Profile.
7.6 Functional and assurance requirements
All Security Assurance Requirements (SAR) have been selected from CC Part 3 [CC3].
All the SFRs have been selected or derived by extension from CC Part 2 [CC2].
It is possible to refer to the Security Target [ST] for the description of all security objectives, the
threats that these objectives should address, the Security Functional Requirements (SFRs) and the
security functions that realize the same objectives.
7.7 Evaluation conduct
The evaluation has been conducted in accordance with the requirements established by the Italian
Scheme for the evaluation and certification of security systems and products in the field of
information technology and expressed in the Provisional Guideline [LGP3] and the Scheme
Information Note [NIS3] and [NIS5] and in accordance with the requirements of the Common Criteria
Recognition Arrangement [CCRA].
The purpose of the evaluation is to provide assurance on the effectiveness of the TOE to meet the
requirements stated in the relevant Security Target [ST]. Initially the Security Target has been
evaluated to ensure that constitutes a solid basis for an evaluation in accordance with the requirements
expressed by the standard CC. Then, the TOE has been evaluated on the basis of the statements
contained in such a Security Target. Both phases of the evaluation have been conducted in accordance
with the CC Part 3 [CC3] and the Common Evaluation Methodology [CEM].
The Certification Body OCSI has supervised the conduct of the evaluation performed by the
evaluation facility (LVS) atsec information security s.r.l.
The evaluation was completed on June 30th
, 2025 with the issuance by LVS of the Evaluation
Technical Report v.2 [ETRv2] that has been approved by the Certification Body on 28 July 2025.
A final version of the ETR was delivered by the LVS on 21 August 2025 [ETRv3] including some
changes requested by the CB.
Then, the Certification Body issued this Certification Report.
Page 19 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
7.8 General considerations about the certification validity
The evaluation focused on the security features declared in the Security Target [ST], with reference
to the operational environment specified therein. The evaluation has been performed on the TOE
configured as described in “Annex B – Evaluated configuration”.
Potential customers are advised to check that this corresponds to their own requirements and to pay
attention to the recommendations contained in this Certification Report.
Certification is not a guarantee that no vulnerabilities exist; there is a probability that exploitable
vulnerabilities can be discovered after the issuance of the certificate.
This Certification Report reflects the conclusions of the certification at the time of issuance. Potential
customers are invited to regularly check the arising of any new vulnerability after the issuance of this
Certification Report, and if the vulnerability can be exploited in the operational environment of the
TOE, check with the Developer if security updates have been developed and if those updates have
been evaluated and certified.
Page 20 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
8 Evaluation outcome
8.1 Evaluation results
Following the analysis of the Evaluation Technical Report v.2 [ETRv2] issued by the LVS atsec
information security s.r.l. and documents required for the certification, and considering the evaluation
activities carried out, the Certification Body OCSI concluded that TOE named “IBM z/OS Version 2
Release 5” meets the requirements of Part 3 of the Common Criteria [CC3] provided for the
evaluation assurance level EAL4 augmented with ALC_FLR.3, with respect to the security features
described in the Security Target [ST] and the evaluated configuration, shown in “Annex B –
Evaluated configuration”.
Table 1 summarizes the final verdict of each activity carried out by the LVS in accordance with the
assurance requirements established in [CC3] for the evaluation assurance level EAL4 augmented with
ALC_FLR.3 (augmentation in italics in Table 1).
Assurance classes and components Verdict
Security Target evaluation Class ASE Pass
Conformance claims ASE_CCL.1 Pass
Extended components definition ASE_ECD.1 Pass
ST introduction ASE_INT.1 Pass
Security objectives ASE_OBJ.2 Pass
Derived security requirements ASE_REQ.2 Pass
Security problem definition ASE_SPD.1 Pass
TOE summary specification ASE_TSS.1 Pass
Development Class ADV Pass
Security architecture description ADV_ARC.1 Pass
Complete functional specification ADV_FSP.4 Pass
Implementation representation of the TSF ADV_IMP.1 Pass
Basic modular design ADV_TDS.3 Pass
Guidance documents Class AGD Pass
Operational user guidance AGD_OPE.1 Pass
Preparative procedures AGD_PRE.1 Pass
Life cycle support Class ALC Pass
Production support, acceptance procedures and automation ALC_CMC.4 Pass
Problem tracking CM coverage ALC_CMS.4 Pass
Delivery procedures ALC_DEL.1 Pass
Identification of security measures ALC_DVS.1 Pass
Systematic flaw remediation ALC_FLR.3 Pass
Page 21 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
Assurance classes and components Verdict
Developer defined life-cycle model ALC_LCD.1 Pass
Well-defined development tools ALC_TAT.1 Pass
Test Class ATE Pass
Analysis of coverage ATE_COV.2 Pass
Testing: basic design ATE_DPT.1 Pass
Functional testing ATE_FUN.1 Pass
Independent testing - sample ATE_IND.2 Pass
Vulnerability assessment Class AVA Pass
Focused vulnerability analysis AVA_VAN.3 Pass
Table 1 Final verdicts for assurance requirements
8.2 Recommendations
The conclusions of the Certification Body (OCSI) are summarized in section 6 (Statement of
Certification).
Potential customers of the product “IBM z/OS Version 2 Release 5” are suggested to properly
understand the specific purpose of the certification by reading this Certification Report together with
the Security Target [ST].
The TOE must be used according to the “Objectives for the Operational Environment” specified in
section 4.2 of the Security Target [ST]. It is assumed that, in the operational environment of the TOE,
all Assumptions described in sections 3.3 and 3.4 of the Security Target [ST] shall be satisfied.
This Certification Report is valid for the TOE in its evaluated configuration; in particular, “Annex A
– Guidelines for the secure usage of the product” includes a number of recommendations relating to
delivery, installation, configuration and secure usage of the product, according to the guidance
documentation provided together with the TOE.
Page 22 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
9 Annex A – Guidelines for the secure usage of the product
This annex provides considerations particularly relevant to the potential customers of the product.
9.1 TOE delivery
9.1.1 Scope of TOE supply
The following table contains the item that comprise the different elements of the TOE including
software and guidance.
No Type Identifier Release Form of
Delivery
z/OS Version 2 Release 5 (z/OS V2.5, program number1
5650-ZOS) Common Criteria Evaluated
Base Package
1 SW z/OS V2.5 Common Criteria Evaluated Base (IBM program
number 5650-ZOS)
V2R5 Electronic
2 DOC DOC z/OS V2.5 Program Directory
Archive file name: e0zpdz40.pdf
SHA256 hashsum of the file:
18fcd09052a6a58dd9a7adb46379f8c3e77eb257ce1c37ad6
6ec65ccaa9049d5
GI11-
9848-
04
Digital
copy
Download from
https://www.ibm.com/docs/en/zos/2.5.0
3 DOC z/OS V2R5 PDF Library
Archive file name: zOS250-Indexed-PDF-package-(Final-
refresh).zip
SHA256 hashsum of the file:
52cfa67733c4e0d2c507e282d7f69f56cc13c7e7a0bbfe2a95
07b86d7daaf056
V2R5 Digital
copy
Download from
https://www.ibm.com/docs/en/zos/2.5.0
1
The "program number" (or "product number") is IBM's technical identification of the product "z/OS". It is used for order
and license purposes and does not uniquely identify the TOE.
Page 23 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
No Type Identifier Release Form of
Delivery
4 DOC z/OS 2.5 Installation Guides
(GA32-0890-50 – Z/OS 2.5 Planning for
Installation)
Archive file name: e0zb100_v2r5.pdf
SHA256 hashsum of the file:
6376e932f19a8468e75a7043086babc5be9fd574c7cd2f247
01a5a464c70ab9c
(SA23-2278-50 – ServerPac Dialog Level: 30 - Using the
Installation Dialog)
Archive file name: gima200_v2r5.pdf
SHA256 hashsum of the file:
d9eded9f48c25544ae20f512be4085e5732719531c853cc99
ff5c8258d643da7
GA32-
0890-
50,
SA23-
2278-
50
Digital
copy
Download from
https://www.ibm.com/docs/en/zos/2.5.0
3 DOC Memo to Customers of z/OS V2.5 Common Criteria
Evaluated Base
Download from:
https://www.ibm.com/software/shopzseries/ShopzSeries_p
ublic.wss
n/a Digital
copy
Download from
https://www.ibm.com/software/shopzseries/ShopzSeries_public.wss
4 DOC [MLSGUIDE] z/OS V2.5 Planning for Multilevel Security
and the Common Criteria
file name: 0ze100_v2r5.pdf
Last updated: 2025-06-16
SHA256 hashsum of the document:
d4011ad5ff77aa3368b0812fb74d3b7a8dceaebf81633fc951
44306dd9cd3efa
GA32-
0891-
50
Digital
copy
Additional Media
5 SW The following APARs (required):
• (Documentation APAR) OA64593
• (Documentation APAR) OA66552
n/a Digital
copy
Page 24 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
No Type Identifier Release Form of
Delivery
• OA56911
• OA57975
• OA60095
• OA62371
• OA66005
These PTFs are to be obtained electronically from
ShopzSeries
(https://www.ibm.com/software/shopzseries)
Table 2 - TOE Deliverables
Page 25 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
9.1.2 Delivery procedure
The evaluated version of z/OS can be ordered via an IBM sales representative or via the ShopzSeries
web application (https://www.ibm.com/software/shopzseries/ShopzSeries_public.wss). When filling
an order via (secured) internet services, IBM requires customers to have an account with a login name
and password. Registration for such an account in turn requires a valid customer ID from IBM.
The TOE order can be delivered to the customer only on digital form (over the internet).
The evaluated version of the TOE can only be ordered by customers already registered with IBM and
requires the IBM sales representative assigned to this customer being involved. As a result, a customer
cannot receive a delivery which he did not order in the first place, at least not without the customer
noting this fact. Because of the individualized order and delivery process, there is no realistic scenario
which a rogue delivery was possible even if IBM had not sent anything or had not received an order
Order content is staged to an IBM download server and Shopz generates a customized download page
for each order. The download page includes links for order content and instructions. A typical z/OS-
only ServerPac order is approximately 20 GB (compressed) in size. A typical subsystem ServerPac
order is approximately 2 GB (compressed) in size.
Subsection "Choosing the Internet download method: Direct or intermediate" explains that with the
Internet delivery option the customer also have to choose whether to download the order directly to
z/OS (recommended) or download it to an intermediate node (a workstation) and then forward it to
the z/OS system:
• if downloading directly to z/OS, integrity of Internet order is ensured by SHA-1 hashing
algorithm and verification if the digital signature is not verified;
• if downloading to a workstation as an intermediate node RSA encryption to create a digital
signature. A unique client and server public/private key pair is created.
CBPDO (Custom-Built Product Delivery Option) and z/OSMF (z/OS Management Facility)
ServerPac order packages are signed by IBM and the digital signature can be optionally verified.
Under subsection "Security of your Internet order", the plan installation guide describes that the
internet delivery method uses a combination of standard authentication and data integrity approaches
to provide security for information about the order and to ensure the integrity of the contents of the
order using Shopz user ID and password.
Hashing algorithms are used for both download methods (directly to z/OS and to a workstation as an
intermediate node). For downloads directly to z/OS, SMP/E ensures the data integrity of the package
through its assignment of a hash value and digital signature during packaging of the order and required
verification of that hash value and optional verification of the digital signature upon download.
SMP/E uses the ICSF One-Way Hash Generate callable service to perform the verification. When
using FTP Secure (FTPS) or HTTP Secure (HTTPS) to download the order directly to the z/OS host
system, the package is encrypted during transmission. When using Download Director to download
the order to a workstation as an intermediate node, the package is encrypted during transmission.
Furthermore, in subsection "Network security" of the IBM web site, the guide explains that before
downloading the order, the customer must understand the network security environment.
• If the customer is planning to download directly to z/OS, he must be familiar with the security and
networking information that is required to navigate his enterprise's firewall or proxy server from
z/OS (for a ServerPac or for CBPDO).
Page 26 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
Server information defines the IBM download server where the order resides. The server
information specifies the IP address or hostname of the IBM download server, and the User ID
and password information to access the IBM download server.
• If the customer is downloading the order to a workstation and he plans to use SMP/E RECEIVE
FROMNETWORK to transfer the order to z/OS, he must update the server information to reflect
the workstation's FTP server information.
Client information describes the IP address or host name of the firewall or proxy server, IP port,
User ID and password, Account information, Firewall-specific or proxy server commands,
Signature keyring if the customer is verifying the package signature.
ServerPac uses the One-Way Hash Generate callable service to verify the SHA-1 hash value
associated with the package. To receive the order by using FTPS, ICSF must be configured and active.
To receive the order by using HTTPS, the SMP/E Java application class must be available.
Finally, the “z/OS Planning for Installation” in subsection "Security for signed software packages"
explains that z/OS SMP/E and z/OSMF Software Management provide the ability to digitally sign
and verify the signature of GIMZIP software packages that are delivered both electronically and
physically, on all supported z/OS releases. This capability ensures that a software package is not
modified since it was created and is signed by the expected provider.
A signed product package contains an SHA-256 hash for each file, and an SHA-256 with RSA
signature for the package.
Both z/OSMF ServerPac and CBPDO order packages are signed by IBM. Observe the following
considerations:
• IBM signs z/OSMF ServerPac portable software instance packages, including all electronic and
DVD packages for all SRELs.
• IBM signs CBPDO order packages, including all electronic and DVD packages for all SRELs.
In addition, the TOE delivery process implies a very special ordering process, indeed the TOE is not
a standard off-the-shelf-product but requires specific hardware to be run on as stated in 1.5.3.2
"Software Configuration" of the [ST], which is only available from IBM and already involves a
business relationship.
9.2 Installation, configuration and secure usage of the TOE
TOE installation, configuration and secure usage should be done by following the instructions in the
appropriate sections of the guidance documentation provided with the product to the customer.
In particular, the documents provided by IBM, as listed in section 9.1.1, contain detailed information
for the secure initialization of the TOE, the preparation of its operational environment and the secure
usage of the TOE in accordance with the security objectives specified in the Security Target [ST].
The following configuration of the TOE is covered by this certification:
The z/OS V2R5 Common Criteria Evaluated Base package must be installed according to the
directions delivered with the media and configured according to the instructions in [MLSGUIDE]
chapter 7. Also, all required PTFs as listed in Table 2 above must be installed.
The installation can exclude any of the elements delivered within the ServerPac, however, user must
install, configure, and use at least the RACF component of the Security Server (available as
optional feature) and the ICSF component of Cryptographic Services.
Page 27 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
The IEASYSxx parmlib OSPROTECT parameter specifies the operating system mitigation mode for
unauthorized programs and users. OSPROTECT must be set to 1 or its equivalent value SYSTEM,
which is the default.
The system must be configured with address space layout randomization (ASLR) enabled for storage
access. This setting is enabled through the following DIAGxx statement: ASLR(YES).
In addition, any software outside the TOE may be added without affecting the security characteristics
of the system, if it cannot run under the following conditions:
• in supervisor state;
• as APF-authorized;
• with keys from 0 through 7;
• with UID(0) or with authority to FACILITY resources BPX.DAEMON, BPX.SERVER, or
BPX.SUPERUSER, or with authority to UNIXPRIV resources.
This explicitly excludes:
• replacement of any element in the ServerPac providing security functions relevant to this
evaluation by other third-party products;
• installation of system exits that run authorized (supervisor state, APF-authorized, or with key 0
through 7), with the exception of default installation exits that are shipped with MVS that do not
compromise security:
o allocated/Offline Device Installation Exit;
o specific Waits Installation Exit;
o volume ENQ Installation Exit;
o volume Mount Exit;
o ASREXIT—SYMREC Authorization Exit;
o IEALIMIT—Limiting User Region Size;
o IEAVTSEL—Post Dump Exit Name List;
o IEFDOIXT—Edit/Check A Caller's Text Units;
o ISGGREX0—Scanning the ENQ/DEQ/RESERVE Resource Name Lists.
With the exception of installation exits that are shipped with RACF that do not compromise
security:
o the sample new password phrase exit, ICHPWX11 (from
SYS1.SAMPLIB(RACEXITS));
o the REXX exec IRRPHREX (from SYS1.SAMPLIB(IRRPHREX)), which is invoked
by ICHPWX11;
• adding user own local checks to the Health Checker for z/OS because those checks run authorized.
If there is the need to add user own checks, add them as unauthorized remote checks;
• using the Authorized Caller Table (ICHAUTAB) in RACF to allow unauthorized programs to
issue RACROUTE REQUEST=VERIFY (RACINIT) or RACROUTE REQUEST=LIST
(RACLIST).
Page 28 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
Digital Certificate Access Server (DCAS), specific configuration options for client authentication and
certificate usage are mandatory with DCAS as:
• DCAS configuration options must specify CLIENTAUTH LOCAL2;
• DCAS configuration options must specify SERVERTYPE CERTTYPE.
SERVERTYPE ALLTYPES and SERVERTYPE USERIDTYPE must not be used;
• Network applications that use DCAS must be controlled by using the resource
EZA.DCAS.system-name in the SERVAUTH class.
The SSH daemon sshd is part of the TOE, if used:
• must be configured to use protocol version 2 and at least one of the AES-based cipher suites stated
in the [ST];
• must be configured to allow only password-based (including password phrase) authentication of
users or public-key based authentication of users with the public keys stored in RACF keyrings.
Host-based and public-key based user authentication with the keys stored elsewhere cannot be
used in the evaluated configuration;
• must be configured with privilege separation enabled. The goal of privilege separation is to prevent
privilege escalation by containing any programming errors within the unprivileged processes;
• it must be configured with the ForwardAgent option set to OFF, which is the default;
• it must be configured with the AuthorizedKeysCommand and AuthorizedPrincipalsCommand
settings disabled.
Data set key protection:
• a data set encryption key must be defined as a protected key;
• a data set encryption key is considered destroyed with the destruction of the master key. The
destruction of the master key results in the immediate invalidation of every key that is
encrypted by the master key. As a result, the data set encryption key is no longer usable.
TLS:
• TLS (Transport Layer Security) processing, if used, can use TLS v.1.2 or TLS v1.3 and must use
one of the cipher suites that are listed in “System SSL” of [MLSGUIDE];
• x.509 client and server certificates must be Elliptic Curve (ECC) NIST Curve 384 or 521, with
SHA-384 or 512 signatures. These certificates must be managed by RACDCERT and their private
keys must be stored in an ICSF PKA key data set (PKDS);
• any application performing client authentication using client digital certificates over TLS must be
configured to use a RACF Key ring. The keyring contains the application certificate and private
key, and the allowed Certificate Authority (CA) certificates that may be used to provide the client
certificates that the application will support. The use of gskkyman for this purpose is not part of
the evaluated configuration; applications cannot enable TLS session renegotiations and must
disable session resumption;
• any application that uses TLS with client or server authentication must be configured for
revocation checking through Online Certification Status Protocol (OCSP) responses;
• N3270 protocol for TSO E is based on the TLS protocol. Therefore, TN3270 must be configured
according to the certified TLS configuration.
Page 29 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
RACF:
• do not use the RACF remote sharing facility (RRSF) in remote mode. If there is the need to use
RRSF in local mode, ensure that command direction cannot be used by taking one of the following
actions:
o ensure that the RRFSFDATA class is not active;
o define the profile DIRECT.* in the RRSFDATA class with UACC(NONE) and no users in the
access list;
• do not use multifactor authentication. User can disable the use of multifactor authentication by
making the MFADEF class inactive.
The following elements and element components cannot be used in the evaluated configuration, either
because they violate the security policies stated in this Security Target or because they have been
removed from the evaluated configuration due to time and resource constraints of the evaluation. As
they are part of the base system, either they must be not configured for use or they must be
deactivated, as described in Chapter 7, "The evaluated configuration for the Common Criteria" in
z/OS Planning for Multilevel Security and the Common Criteria [MLSGUIDE]:
• Apache Server;
• BCPii;
• All Bulk Data Transfer (BDT) elements: BDT (FMID HBD6602), BDT File-to-File (FMID
JBD6201), and BDT Systems Network Architecture (SNA) NJE (FMID JBD6202);
• The DF Server Message Block (SMB) from the element zFS File System;
• Infoprint Server (FMIDs HMOS705, HNET7C0, HOPI7B0);
• JES3 (FMID HJS77B0);
• Kerberos;
• LDAP;
• NFS;
• PKI Services;
• SUDO;
In addition, the following cannot be used in the certified configuration (they must be not
configured for use or they must be deactivated):
• the Advanced Program-to-Program Communication / Multiple Virtual Storage (APPC/MVS)
component of the BCP;
• the DFSMS Object Access Method for content management type applications;
• the RACF remote sharing facility in remote mode;
• the multi-level security environment;
• JES2 NJE communication via TCP/IP. JES2 NJE must use SNA or BSC in the certified
configuration;
• JES2 Execution Batch Monitor (XBM) facility.
Page 30 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
The [MLSGUIDE] in section "Boundary checking is enabled" of chapter 7 states that in the certified
configuration, applications that are written in a language for which the compiler supports boundary
checking, such as a stack protection mechanism, must enable boundary checking.
The [MLSGUIDE] in section "System configuration" of chapter 7 describes in its subsections the
requirements for the certified system's configuration.
Page 31 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
10 Annex B – Evaluated configuration
The Target of Evaluation is “z/OS Version 2 Release 5”, developed by IBM Corp. The TOE is
software only and is accompanied by guidance documentation. The items listed in Table 2 represent
the TOE.
The TOE name and version number uniquely identify the TOE and its components, which constitute
the evaluated configuration of the TOE verified by the Evaluator at the time they perform the tests
and to which the evaluation results apply.
10.1 TOE operational environment
The TOE is running a logical partition provided by PR/SM or a certified version of z/VM on one of
the following z System processors:
• IBM z16 with CPACF DES/TDES Enablement Feature 3863 active, with Crypto Express8S
(CEX8) cards.
The assumptions about the technical environment in which the TOE is intended to be used are
reported in section 3.3. of [ST].
Page 32 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
11 Annex C – Test activity
This annex describes the task of both the Evaluators and the Developer in testing activities.
11.1 Test configuration
The test systems were running “z/OS Version 2 Release 5” in the evaluated configuration.
The Security Target requires the software packages comprising the TOE to be run on an abstract
machine implementing the z/Architecture machine interface as defined in the "z/Architecture
Principles of Operation" [ZARCH]. The hardware platforms implementing this abstract machine are:
• IBM z16 with CPACF DES/TDES Enablement Feature 3863 active, with Crypto Express8S
(CEX8) cards.
Note that the above mentioned CryptoExpress cards are not part of z/OS and therefore the
implementation of the cryptographic functions provided by those cards has not been analyzed.
Testing has been performed using those cards to ensure that TOE operates correctly with the
cryptographic functions provided by those cards . The claims made in the Security Target concerning
the cryptographic functions therefore apply to those functions implemented in software.
The TOE may be running on machines within a logical partition provided by a certified version of
IBM PR/SM. In addition, the TOE may run on a virtual machine provided by a certified version of
IBM z/VM. Tests have been performed using the z/VM environment.
For the peripherals that can be used with the TOE, please refer to the [ST], section 1.5.3.2.
All testing activities have been carried out remotely from the LVS premises having full and exclusive
control on the test machine as per [NIS5].
11.2 Functional tests performed by the Developer
Due to the massive number of tests, testing was performed throughout the development of the TOE.
To ensure proper testing of all security relevant behaviour of the TOE, the Evaluators verified that all
tests, that might have been affected by any security-relevant change introduced late in the
development cycle, had been run.
11.2.1 Test approach
FVT for z/OS is largely performed on the VICOM test system. This is an enhanced z/VM system
implementing the z/Architecture abstract machine interface. It allows testers to bring up individual,
virtual test machines running z/OS with access to virtualized peripherals such as disks and network
connections. For the purpose of the security function tests, this environment is fully equivalent to the
machines running z/OS. This environment was also used by the Evaluators for their independent
testing.
IBM has provided a common test framework for tests that can be automated. The BERD (Background
Environment Random Driver) test driver submits the testcases as JES jobs. IBM's intention is to move
more and more tests to this automated environment, which will ease the test effort required for the
evaluations substantially. Most test teams ran their manual tests in the so-called “Communication
Security” (COMSEC) test environment, which provides a complete test environment in the evaluated
configuration of the TOE in the different modes of operation.
Page 33 of 35 OCSI/CERT/ATS/07/2024/RC Ver. 1.0
The Developer provided a pre-installed system image for VICOM and for the machines running the
COMSEC tests. The additional PTFs were applied to the VICOM and COMSEC systems as they
became available.
IBM’s general test approach is defined in the process for Integrated Product Development (IPD) with
Developer tests, FVT, and System Verification Tests (SVT). FVT and SVT test is performed by test
teams, with testers being independent from the Developer. The different test teams have developed
their own individual test and test documentation tools, but all implement the requirements set forth
in the IPD documentation.
For the purpose of the evaluation, FVT is of interest to the Evaluators, since the single security
functions claimed in the [ST] are tested here. IBM decided to create a test bucket with the tests for
the security functions, summarizing the tests in individual test plans, so that the Evaluators had a
chance to deal with the otherwise overwhelming complexity of the z/OS testing.
IBM's test strategy for the evaluation had three cornerstones:
• The major internal security interface was the interface to RACF, which is tested exhaustively
by the RACF test group.
• Components requiring Identification and Authentication or Access Control services call
RACF. For most of these services, it is sufficient to demonstrate that these interfaces call
RACF, once the testing of the RACF interface (see above) has established confidence in the
correct inner workings of RACF.
• Due to the design of z/OS, a large number of internal interfaces is also visible externally,
although the interfaces are not intended to be called by external, unprivileged subjects. For
these interfaces, which are basically authorized programs, operator commands, certain
callable services, SVC and PC routines, testing established only that these interfaces cannot
be called by unauthorized callers.
Apart from these tests, all components providing external interfaces for security functions were tested
intensively. For the current version of z/OS this included additional tests for enhancements of the
already existing TOE components. All new test cases were determined to follow the approach of the
already existing tests for the respective component.
For components providing cryptographic functions, testing was performed with and without hardware
cryptographic support in order to test the correct usage of the hardware cryptographic functions, if
present, and the correct implementation of the software implementation within the TOE.
11.2.2 Test Coverage
The Evaluators verified the complete coverage between the test cases in the test documentation
provided by Developer and the TSFIs described in the functional specification. The Evaluators
verified that the test cases are sufficient to demonstrate the internal behaviour and properties of the
TSF.
11.2.3 Test results
The actual test results of all Developer’s tests were consistent with the expected ones.
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11.3 Functional and independent tests performed by the Evaluators
11.3.1 Test approach
The Evaluators performed tests following the CEM approach to test every security function, without
striving for exhaustive testing: Evaluators devised a test strategy for the tests they intended to re-run
from the developer's tests and the set of tests they were developing themselves.
The Evaluator performed testing remotely by connecting to the test environment using IBM hardened
laptops. The Developer set up the test environment with the actual TOE model in Poughkeepsie, New
York, USA. The testing was performed between January and March 2025.
11.3.2 Test result
The Evaluators involved in the tests decided to focus the sampling based on [ST] functional claims
related to TOE security functions.
Changes that were new in V2R5 are classified as major. With this concept in mind, the sampling of
the Evaluators is based on the re-execution of the tests associated with a major claim or one that has
undergone an update since the previous evaluation (minor).
Finally, the Evaluators consider the strategy used to be reasonable also because the security functions
of the “core” system had already been investigated several times, and no indication had been found
throughout the evaluation that any changes in the system behaviour could be expected for the
unchanged security functionality.
The Evaluators chose to observe the developer tests while they performed a sample of their test cases.
This setup was preferred to setting up an own instance of COMSEC, which would have required the
transfer of all instrumentation software to that system. Rather, the Evaluators decided to observe test
runs from the different test teams, which would also allow them to interview the testers and
understand their tests and methodology in a more efficient manner than from the investigation of the
test documentation alone. Therefore, the Evaluators scheduled a series of test sessions with the
different test teams.
The sampled developer’s tests were run successfully, and the Evaluators verified the correct
behaviour of the TSFIs and TSFs and the correspondence between expected results and achieved
results for each test.
All test cases devised by the Evaluators were run successfully and all the test results were consistent
to the expected test results.
11.4 Vulnerability analysis and penetration tests
For the execution of these activities, the Evaluators worked on the test environment and TOE already
used for the functional test activities, verifying that the TOE and the test environment were properly
configured.
The Evaluator analysed the Security Target [ST], design documentation, and test results for potential
vulnerabilities. In addition, the Evaluators performed a search on public sources for known potential
vulnerabilities of the TOE or components of the TOE. After an analysis of different potential
vulnerabilities, the Evaluator devise the following three penetration tests:
• interfering with the password change function;
• checking for correct storage key validations on legacy SVC system calls;
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• attempt to exhaust memory space used by z/OS for storing task control blocks.
The Evaluators could then conclude that the TOE is resistant to an attack potential of Enhanced Basic
in its intended operating environment. No exploitable or residual vulnerabilities have been identified.