IBM z/OS Default profiles must not be defined in TSS OMVS UNIX security parameters for classified systems.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-224090TSS0-US-000170SV-224090r991589_ruleCCI-000366medium
Description
Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements.
STIGDate
IBM z/OS TSS Security Technical Implementation Guide2025-06-24

Details

Check Text (C-224090r991589_chk)

If the system in not classified this is not applicable. From a command line issue the following command: TSS MODIFY STATUS Note: One must have appropriate access to perform this command (have the site security officer to issue command). If system is classified and UNIQUSER is off i.e., (UNIQUSER(OFF) this is not a finding.

Fix Text (F-25751r516670_fix)

Ensure that Use of the OMVS default UIDs will not be allowed on any classified system. Set Control Option UNIQUSER off.