TMA-ROS1-1.5.1

Ensure permissions on bootloader config are configured

MediumLevel 1Automatedros

Description

The grub configuration file contains information on boot settings and passwords for unlocking boot options. The grub configuration is usually grub.cfg stored in /boot/grub/. The audit requires /boot/grub/grub.cfg owned by root:root with no group or other permissions. Host-level control from the CIS ROS Melodic benchmark (Ubuntu 18.04 robot hosts); run as root.

How it is checked

Audit method: Shell command

shell

[ -e /boot/grub/grub.cfg ] || { echo '/boot/grub/grub.cfg not found'; exit 1; }
set -- $(stat -Lc '%a %u %g' /boot/grub/grub.cfg) || exit 1
m=$((8#$1)); [ $((m & ~8#0700)) -eq 0 ] || { echo "/boot/grub/grub.cfg mode $1 exceeds 0700"; exit 1; }
[ "$2" = 0 ] || { echo "/boot/grub/grub.cfg uid $2"; exit 1; }
case " 0 " in *" $3 "*) echo compliant ;; *) echo "/boot/grub/grub.cfg gid $3" ;; esac

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Run the following commands to set permissions on your grub configuration: # chown root:root /boot/grub/grub.cfg # chmod og-rwx /boot/grub/grub.cfg

Properties

Operating systems: Any
Tags: rosros1melodicsystem
Reference: CIS ROS Melodic Benchmark v1.0.0 - 1.5.1 Ensure permissions on bootloader config are configured

Check this host

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

shell

tmaegis scan --target ros