Title

IBM z/OS attributes of z/OS UNIX user accounts must have a unique GID in the range of 1-99. (Cat II impact)

Discussion

To assure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system. Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following: 1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and 2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity.

Check Content

A site can choose to have both an OMVSGRP group and an STCOMVS group or combine the groups under one of these names. If OMVSGRP and/or STCOMVS groups are defined and have a unique GID in the range of 1-99, this is not a finding.

Fix Text

Define the OMVSGRP group and/or the STCOMVS group to the security database with a unique GID in the range of 1-99. OMVSGRP is the name suggested by IBM for all the required userids. STCOMVS is the standard name used at some sites for the userids that are associated with z/OS UNIX started tasks and daemons. These groups can be combined at the site's discretion.

Additional Identifiers

Rule ID: SV-224092r877930_rule

Vulnerability ID: V-224092

Group Title: SRG-OS-000104-GPOS-00051

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.