Information
If the operating system is using Unified Extensible Firmware Interface (UEFI) it must require authentication upon booting into single-user and maintenance modes.
Rationale:
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 and is designed to require a password to boot into single-user mode or make modifications to the boot menu.
Solution
Create an encrypted password with grub2-setpassword:
# grub2-setpassword
Enter password: <password>
Confirm password: <password>
Edit the /boot/efi/EFI/redhat/grub.cfg file and add or modify the following lines in the ### BEGIN /etc/grub.d/01_users ### section:
Example: vim /boot/efi/EFI/redhat/grub.cfg
set superusers='root'
export superusers
Run the following command to update the grub2 configuration:
# grub2-mkconfig -o /boot/grub2/grub.cfg
Impact:
This recommendation is only valid for Amazon Linux 2 when it is used on-premise.
Notes:
This Benchmark recommendation maps to:
Red Hat Enterprise Linux 7 Security Technical Implementation Guide:
Version 2, Release: 3 Benchmark Date: 26 Apr 2019
Vul ID: V-81007
Rule ID: SV-95719r1_rule
STIG ID: RHEL-07-010491
Severity: CAT I