Systems using Unified Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user and maintenance modes.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-71963	RHEL-07-010490	SV-86587r3_rule		High

Description
If the system does not require valid root authentication before it boots into single-user or maintenance mode, anyone who invokes single-user or maintenance mode is granted privileged access to all files on the system. GRUB 2 is the default boot loader for RHEL 7 and is designed to require a password to boot into single-user mode or make modifications to the boot menu.

STIG	Date
Red Hat Enterprise Linux 7 Security Technical Implementation Guide	2017-12-14

Details

Check Text ( C-72195r3_chk )
For systems that use BIOS, this is Not Applicable. Check to see if an encrypted root password is set. On systems that use UEFI, use the following command: # grep -i password /boot/efi/EFI/redhat/grub.cfg password_pbkdf2 [superusers-account] [password-hash] If the root password entry does not begin with "password_pbkdf2", this is a finding. If the "superusers-account" is not set to "root", this is a finding.

Check Text ( C-72195r3_chk )

For systems that use BIOS, this is Not Applicable.

Check to see if an encrypted root password is set. On systems that use UEFI, use the following command:

# grep -i password /boot/efi/EFI/redhat/grub.cfg

password_pbkdf2 [superusers-account] [password-hash]

If the root password entry does not begin with "password_pbkdf2", this is a finding.

If the "superusers-account" is not set to "root", this is a finding.

Fix Text (F-78315r2_fix)
Configure the system to encrypt the boot password for root. Generate an encrypted grub2 password for root with the following command: Note: The hash generated is an example. # grub2-mkpasswd-pbkdf2 Enter Password: Reenter Password: PBKDF2 hash of your password is grub.pbkdf2.sha512.10000.F3A7CFAA5A51EED123BE8238C23B25B2A6909AFC9812F0D45 Edit "/etc/grub.d/40_custom" and add the following lines below the comments: # vi /etc/grub.d/40_custom set superusers="root" password_pbkdf2 root {hash from grub2-mkpasswd-pbkdf2 command} Generate a new "grub.conf" file with the new password with the following commands: # grub2-mkconfig --output=/tmp/grub2.cfg # mv /tmp/grub2.cfg /boot/efi/EFI/redhat/grub.cfg

Fix Text (F-78315r2_fix)

Configure the system to encrypt the boot password for root.

Generate an encrypted grub2 password for root with the following command:

Note: The hash generated is an example.

# grub2-mkpasswd-pbkdf2

Enter Password:
Reenter Password:
PBKDF2 hash of your password is grub.pbkdf2.sha512.10000.F3A7CFAA5A51EED123BE8238C23B25B2A6909AFC9812F0D45

Edit "/etc/grub.d/40_custom" and add the following lines below the comments:

# vi /etc/grub.d/40_custom

set superusers="root"

password_pbkdf2 root {hash from grub2-mkpasswd-pbkdf2 command}

Generate a new "grub.conf" file with the new password with the following commands:

# grub2-mkconfig --output=/tmp/grub2.cfg
# mv /tmp/grub2.cfg /boot/efi/EFI/redhat/grub.cfg