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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-11946	GEN000340	SV-37155r1_rule	ECSC-1	Medium

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

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

Details

Check Text ( C-35863r2_chk )
Check the UID assignments for all accounts. # cut -d: -f 1,3 /etc/passwd | egrep ":[1-4][0-9]{2}$|:[0-9]{1,2}$" Confirm all accounts with a UID of 499 and below are used by a system account. If a UID reserved for system accounts (0 - 499) is used by a non-system account, then this is a finding.

Fix Text (F-31119r1_fix)
Change the UID numbers for non-system accounts with reserved UIDs (those less or equal to 499).