cis-ubuntu1204-v110-3-3

name	cis-ubuntu1204-v110-3-3
description	Set Boot Loader Password
category	cis-os-hardening
version	1.1.0
author	cyberstrike-official
tags	["cis","ubuntu",12.04,"linux","boot","grub","password","authentication"]
cis_id	3.3
cis_benchmark	CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

3.3 Set Boot Loader Password (Scored)

Profile Applicability

• Level 1

Description

Setting the boot loader password will require that anyone rebooting the system must enter a password before being able to set command line boot parameters.

Rationale

Requiring a boot password upon execution of the boot loader will prevent an unauthorized user from entering boot parameters or changing the boot partition. This prevents users from weakening security (e.g. turning off SELinux at boot time).

Audit Procedure

Using Command Line

Perform the following to determine if a password is required to set command line boot parameters:

grep "^set superusers" /boot/grub/grub.cfg
grep "^password" /boot/grub/grub.cfg

Expected Result

The first command should return: set superusers="<user-list>" The second command should return: password_pbkdf2 <user> <encrypted password> At least one user must be specified as a super user and have a password assigned.

Remediation

Using Command Line

Create an encrypted password with grub-mkpasswd-pbkdf2:

grub-mkpasswd-pbkdf2

Add the following into /etc/grub.d/00_header or a custom /etc/grub.d configuration file:

cat <<EOF
set superusers="<user-list>"
password_pbkdf2 <user> <encrypted-password>
EOF

Run the following to update the grub configuration:

update-grub

Default Value

By default, no boot loader password is set.

References

• CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 1 - Scored