TMA-BIND-2.3

Lock the BIND User Account

MediumLevel 1Automatedbind

Description

The user account under which BIND runs should not have a valid password, but should be locked. The audit reads /etc/shadow (root) and requires the password field of the named (or bind) account to start with ! or * (locked, what passwd -S reports as LK/L).

How it is checked

Audit method: Shell command

shell

[ -r /etc/shadow ] || exit 1
bad=0; n=0
for u in named bind; do
  p=$(awk -F: -v u=$u '$1==u{print $2; f=1} END{if(!f) print "-"}' /etc/shadow)
  [ "$p" = - ] && continue; n=1
  case "$p" in '!'*|'*'*) ;; *) echo "$u account is not locked"; bad=1 ;; esac
done
[ "$n" -eq 1 ] || { echo 'no named/bind account in /etc/shadow'; exit 1; }
[ "$bad" -eq 0 ] && echo compliant

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

To remediate, lock the named account using the password command with the lock option as shown below. # passwd -l named Locking password for user named. passwd: Success

Properties

Operating systems: Any
Tags: binddnspermissions
Reference: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 2.3 Lock the BIND User Account

Check this host

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

shell

tmaegis scan --target bind