Ensure accounts without a valid login shell are locked

How it is checked

Audit method: Shell command

alt0() { o=$(bash -c '#!/usr/bin/env bash

{
   l_valid_shells="^($(awk -F\/ '"'"'$NF != "nologin" {print}'"'"' /etc/shells | sed -rn '"'"'/^\//{s,/,\\\\/,g;p}'"'"' | paste -s -d '"'"'|'"'"' - ))$"
   while IFS= read -r l_user; do
      passwd -S "$l_user" | awk '"'"'$2 !~ /^L/ {print "Account: \"" $1 "\" does not have a valid login shell and is not locked"}'"'"'
   done < <(awk -v pat="$l_valid_shells" -F: '"'"'($1 != "root" && $(NF) !~ pat) {print $1}'"'"' /etc/passwd)
}' 2>&1); [ -z "$o" ] || { echo "step1: $o" | head -c 300; return 1; }; }; if alt0; then echo compliant; fi

Expected output

compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Run the following command to lock any non-root accounts without a valid login shell returned by the audit: # usermod -L <user> Example script:: #!/usr/bin/env bash { l_valid_shells="^($(awk -F\/ '$NF != "nologin" {print}' /etc/shells | sed -rn '/^\//{s,/,\\\\/,g;p}' | paste -s -d '|' - ))$" while IFS= read -r l_user; do passwd -S "$l_user" | awk '$2 !~ /^L/ {system ("usermod -L " $1)}' done < <(awk -v pat="$l_valid_shells" -F: '($1 != "root" && $(NF) !~ pat) {print $1}' /etc/passwd) }

Check this host

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

tmaegis scan --target linux