The root account must be the only account having unrestricted access to the system.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-214999	UBTU-16-010670	SV-214999r610931_rule		High

Description
If an account other than root also has a User Identifier (UID) of "0", it has root authority, giving that account unrestricted access to the entire Ubuntu operating system. Multiple accounts with a UID of "0" afford an opportunity for potential intruders to guess a password for a privileged account.

STIG	Date
Canonical Ubuntu 16.04 LTS Security Technical Implementation Guide	2020-12-09

Details

Check Text ( C-16198r284865_chk )
Check the Ubuntu operating system for duplicate User ID (UID) "0" assignments with the following command: # awk -F: '$3 == 0 {print $1}' /etc/passwd root If any accounts other than root have a UID of "0", this is a finding.

Fix Text (F-16196r284866_fix)
Change the User ID (UID) of any account on the system, other than root, that has a UID of "0". If the account is associated with system commands or applications, the UID should be changed to one greater than "0" but less than "1000". Otherwise, assign a UID of greater than "1000" that has not already been assigned.