Cis Ubuntu2004 V300 1 3 1 2

1.3.1.2 Ensure AppArmor is enabled in the bootloader configuration (Automated)

Profile

• Level 1 - Server
• Level 1 - Workstation

Description

Configure AppArmor to be enabled at boot time and verify that it has not been overwritten by the bootloader boot parameters.

Note: This recommendation is designed around the grub bootloader, if LILO or another bootloader is in use in your environment enact equivalent settings.

Rationale

AppArmor must be enabled at boot time in your bootloader configuration to ensure that the controls it provides are not overridden.

Audit Procedure

Command Line

Run the following command to verify that all linux lines have the apparmor=1 parameter set:

# grep "^\s*linux" /boot/grub/grub.cfg | grep -v "apparmor=1"

Nothing should be returned.

Run the following command to verify that all linux lines have the security=apparmor parameter set:

# grep "^\s*linux" /boot/grub/grub.cfg | grep -v "security=apparmor"

Nothing should be returned.

Expected Result

No output should be returned for either command, indicating all linux lines have both apparmor=1 and security=apparmor parameters set.

Remediation

Command Line

Edit /etc/default/grub and add the apparmor=1 and security=apparmor parameters to the GRUB_CMDLINE_LINUX= line:

GRUB_CMDLINE_LINUX="apparmor=1 security=apparmor"

Run the following command to update the grub2 configuration:

# update-grub

References

1. NIST SP 800-53 Rev. 5: AC-3

CIS Controls

MITRE ATT&CK Mappings: T1068, T1068.000, T1565, T1565.001, T1565.003 | TA0003 | M1026