The Ubuntu operating system must be configured so that Advance Package Tool (APT) removes all software components after updated versions have been installed.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-238370	UBTU-20-010449	SV-238370r853447_rule		Medium

Description
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by adversaries. Some information technology products may remove older versions of software automatically from the information system.

STIG	Date
Canonical Ubuntu 20.04 LTS Security Technical Implementation Guide	2023-06-02

Details

Check Text ( C-41580r654283_chk )
Verify is configured to remove all software components after updated versions have been installed with the following command: $ grep -i remove-unused /etc/apt/apt.conf.d/50unattended-upgrades Unattended-Upgrade::Remove-Unused-Dependencies "true"; Unattended-Upgrade::Remove-Unused-Kernel-Packages "true"; If the "::Remove-Unused-Dependencies" and "::Remove-Unused-Kernel-Packages" parameters are not set to "true" or are missing or commented out, this is a finding.

Check Text ( C-41580r654283_chk )

Verify is configured to remove all software components after updated versions have been installed with the following command:

$ grep -i remove-unused /etc/apt/apt.conf.d/50unattended-upgrades
Unattended-Upgrade::Remove-Unused-Dependencies "true";
Unattended-Upgrade::Remove-Unused-Kernel-Packages "true";

If the "::Remove-Unused-Dependencies" and "::Remove-Unused-Kernel-Packages" parameters are not set to "true" or are missing or commented out, this is a finding.

Fix Text (F-41539r654284_fix)
Configure APT to remove all software components after updated versions have been installed. Add or updated the following options to the "/etc/apt/apt.conf.d/50unattended-upgrades" file: Unattended-Upgrade::Remove-Unused-Dependencies "true"; Unattended-Upgrade::Remove-Unused-Kernel-Packages "true";