SUSE operating systems with Unified Extensible Firmware Interface (UEFI) implemented must require authentication upon booting into single-user mode and maintenance.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-77145	SLES-12-010440	SV-91841r5_rule		Medium

Description
If the system allows a user to boot into single-user or maintenance mode without authentication, any user that invokes single-user or maintenance mode is granted privileged access to all system information. If the system is running in EFI mode, SLES 12 by default will use GRUB 2 EFI as the boot loader.

STIG	Date
SLES 12 Security Technical Implementation Guide	2020-06-30

Details

Check Text ( C-76755r4_chk )
Verify that the SUSE operating system has set an encrypted boot password. Note: If the system does not use Unified Extensible Firmware Interface (UEFI) this requirement is Not Applicable. Check that the encrypted password is set for a boot user with the following command: # sudo cat /boot/efi/EFI/sles/grub.cfg \| grep -i password password_pbkdf2 boot grub.pbkdf2.sha512.10000.VeryLongString If the boot user password entry does not begin with "password_pbkdf2", this is a finding.

Check Text ( C-76755r4_chk )

Verify that the SUSE operating system has set an encrypted boot password.

Note: If the system does not use Unified Extensible Firmware Interface (UEFI) this requirement is Not Applicable.

Check that the encrypted password is set for a boot user with the following command:

# sudo cat /boot/efi/EFI/sles/grub.cfg | grep -i password

password_pbkdf2 boot grub.pbkdf2.sha512.10000.VeryLongString

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

Fix Text (F-83841r5_fix)
Note: If the system does not use UEFI, this requirement is Not Applicable. Configure the SUSE operating system to encrypt the boot password. Generate an encrypted (GRUB 2) password for a boot user with the following command: # sudo grub2-mkpasswd-pbkdf2 Enter Password: Reenter Password: PBKDF2 hash of your password is grub.pbkdf2.sha512.10000.MFU48934NJD84NF8NSD39993JDHF84NG Using the hash from the output, modify the "/etc/grub.d/40_custom" file with the following command to add a boot password for the root entry: # cat << EOF set superusers="boot" password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongString EOF Generate an updated "grub.conf" file with the new password using the following commands: # sudo grub2-mkconfig --output=/tmp/grub2.cfg # sudo mv /tmp/grub2.cfg /boot/efi/EFI/sles/grub.cfg

Fix Text (F-83841r5_fix)

Note: If the system does not use UEFI, this requirement is Not Applicable.

Configure the SUSE operating system to encrypt the boot password.

Generate an encrypted (GRUB 2) password for a boot user with the following command:

# sudo grub2-mkpasswd-pbkdf2
Enter Password:
Reenter Password:
PBKDF2 hash of your password is grub.pbkdf2.sha512.10000.MFU48934NJD84NF8NSD39993JDHF84NG

Using the hash from the output, modify the "/etc/grub.d/40_custom" file with the following command to add a boot password for the root entry:

# cat << EOF
set superusers="boot"
password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongString
EOF

Generate an updated "grub.conf" file with the new password using the following commands:

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