The root account must be the only account having a UID of 0.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-773	GEN000880	SV-64341r1_rule		Medium

Description
If an account has a UID of 0, it has root authority. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account.

STIG	Date
Oracle Linux 5 Security Technical Implementation Guide	2020-02-25

Details

Check Text ( C-52745r1_chk )
Check the system for duplicate UID 0 assignments by listing all accounts assigned UID 0. Procedure: # awk -F: '($3 == 0) { print $1 }' /etc/passwd If any accounts other than root are assigned UID 0, this is a finding.

Fix Text (F-54927r1_fix)
Remove or change the UID of accounts other than root that have UID 0.