Vulnerability Discussion
An account has root authority if it has a user identifier (UID) of "0". Multiple accounts with a UID of "0" afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.
Check
Verify that only the "root" account has a UID "0" assignment 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
Change the 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.