CA-ACF2 must limit Write and Allocate access to all APF-authorized libraries to system programmers only.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
high	V-223449	SRG-OS-000080-GPOS-00048	ACF2-ES-000280	SV-223449r958472_rule	2025-03-11	9

Description
To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DoD-approved PKIs, all DoD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include: identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include: access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. Satisfies: SRG-OS-000080-GPOS-00048, SRG-OS-000259-GPOS-00100, SRG-OS-000324-GPOS-00125

Description

To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DoD-approved PKIs, all DoD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include: identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include: access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. Satisfies: SRG-OS-000080-GPOS-00048, SRG-OS-000259-GPOS-00100, SRG-OS-000324-GPOS-00125

ℹ️ Check
From Any ISPF input line, enter: TSO ISRDDN APF If all of the following are untrue, this is not a finding. If any of the following is true, this is a finding. - The ACP data set rules for APF libraries do not restrict WRITE and/or ALLOCATE access to only z/OS systems programming personnel. - The ACP data set rules for APF libraries do not specify that all (i.e., failures and successes) WRITE and/or ALLOCATE access will be logged.

ℹ️ Check

From Any ISPF input line, enter: TSO ISRDDN APF If all of the following are untrue, this is not a finding. If any of the following is true, this is a finding. - The ACP data set rules for APF libraries do not restrict WRITE and/or ALLOCATE access to only z/OS systems programming personnel. - The ACP data set rules for APF libraries do not specify that all (i.e., failures and successes) WRITE and/or ALLOCATE access will be logged.

✔️ Fix
Review access authorization to critical system files. Evaluate the impact of correcting the deficiency. Develop a plan of action and implement the changes required to protect APF Authorized Libraries. Configure Update and Allocate access to all APF-authorized libraries to be limited to system programmers only and all update and alter access is logged.