Ensure usernames and UIDs are unique

How it is checked

Audit method: Shell command

command -v cut >/dev/null 2>&1 || exit 1; out=$( { cut -d: -f3 /etc/passwd | sort -n | uniq -d; cut -d: -f1 /etc/passwd | sort | uniq -d ; } 2>/dev/null ); [ -z "$out" ] && echo compliant || printf '%s\n' "$out" | head -n 20

Expected output

compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Examine the user IDs of all configured accounts: cut -d: -f 3 /etc/passwd | sort -n | uniq -d If a number, or numbers are returned from the command above, these are UID values which are not unique within the /etc/passwd file. Determine the effected accounts/s: cut -d: -f 1 /etc/passwd | sort -n | uniq -d | while read UID; do cut -f "1 3" -d : /etc/passwd |grep ":${UID}" done Examine the usernames IDs of all configured accounts: cut -d: -f 1 /etc/passwd | sort -n | uniq -d If a username, or usernames are returned from the command above, these are username values which are not unique within the /etc/passwd file. Determine the effected accounts/s: cut -d: -f 1 /etc/passwd | sort -n | uniq -d | while read username; do cut -f "1 3" -d : /etc/passwd |grep "${username}:" done NOTE: Any account names returned should either be deleted or have the UID changed To remove: rmuser <username> To change the UID: chuser id=<id> <username>

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

tmaegis scan --target aix