Title

GIDs reserved for system accounts must not be assigned to non-system groups. (Cat II impact)

Discussion

Reserved GIDs are typically used by system software packages. If non-system groups have GIDs in this range, they may conflict with system software, possibly leading to the group having permissions to modify system files.

Check Content

Confirm all accounts with a GID of 99 and below are used by a system account. If a GID reserved for system accounts (0 - 99) is used by a non-system account, this is a finding. The vendor-supplied system default group "users" (gid=20) is considered an exception to this check. # cat /etc/passwd | cut -f 1,4 -d ":"

Fix Text

Change the primary group GID numbers for non-system accounts with reserved primary group GIDs (those less or equal to 99). # usermod -g <new_group> <user>

Additional Identifiers

Rule ID: SV-38454r1_rule

Vulnerability ID: V-780

Group Title: GEN000360

Expert Comments

CCIs tied to check.

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