IBM z/OS DFSMS resource class(es) must be defined to the GSO CLASMAP record in accordance with security requirements.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-223593	ACF2-SM-000010	SV-223593r958472_rule		Medium

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. The system-wide options control the default settings for determining how the ACP will function when handling requests for access to the operating system environment, ACP, and customer data. The ACP provides the ability to set a number of these fields at the subsystem level. If no setting is found, the system-wide defaults will be used. The improper setting of any one of these fields, individually or in combination with another, can compromise the security of the processing environment. In addition, failure to establish standardized settings for the ACP control options introduces the possibility of exposure during a migration process or contingency plan activation.

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. The system-wide options control the default settings for determining how the ACP will function when handling requests for access to the operating system environment, ACP, and customer data. The ACP provides the ability to set a number of these fields at the subsystem level. If no setting is found, the system-wide defaults will be used. The improper setting of any one of these fields, individually or in combination with another, can compromise the security of the processing environment. In addition, failure to establish standardized settings for the ACP control options introduces the possibility of exposure during a migration process or contingency plan activation.

STIG	Date
IBM z/OS ACF2 Security Technical Implementation Guide	2024-06-24

Details

Check Text ( C-25266r836678_chk )
From the ISPF Command Shell enter: ACF SET CONTROL(GSO) SHOW CLASMAP If both MGMTCLAS and STORCLAS resource classes are uniquely defined (i.e., not type SAF), this is not a finding.

Fix Text (F-25254r836679_fix)
Define the GSO CLASMAP record with the following definitions: MGMTCLAS STORCLAS Ensure both resource classes above are defined uniquely. Example: SHOW SAFDEF SET CONTROL(GSO) INSERT CLASMAP.MGMTCLAS RESOURCE(MGMTCLAS) RSRCTYPE(MGM) ENTITYTLN(8) INSERT CLASMAP.STORCLAS RESOURCE(STORCLAS) RSRCTYPE(STR) ENTITYTLN(8 F ACF2,REFRESH(ALL)