GIDs reserved for system accounts must not be assigned to non-system groups.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-780	GEN000360	SV-37157r1_rule	ECSC-1	Medium

Description
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.

STIG	Date
Red Hat Enterprise Linux 5 Security Technical Implementation Guide	2017-03-01

Details

Check Text ( C-35866r1_chk )
Confirm all accounts with a GID of 499 and below are used by a system account. Procedure: List all the users with a GID of 0-499. # cut -d: -f 1,4 /etc/passwd|egrep ":[1-4][0-9]{2}$|:[0-9]{1,2}$" If a GID reserved for system accounts (0 - 499) is used by a non-system account, this is a finding.

Fix Text (F-31121r1_fix)
Change the primary group GID numbers for non-system accounts with reserved primary group GIDs (those less or equal to 499).