apt_get should be configured to remove previous software components after new versions have been installed. To configure apt_get to remove the previous software components after updating, set the ::Remove-Unused-Dependencies and ::Remove-Unused-Kernel-Packages to true in /etc/apt/apt.conf.
Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by some adversaries.
The gpgcheck option controls whether RPM packages' signatures are always checked prior to installation. To configure apt_get to check package signatures before installing them, ensure the following line appears in /etc/apt/apt.conf in the [main] section:
gpgcheck=1
Changes to any software components can have significant effects on the
overall security of the operating system. This requirement ensures the
software has not been tampered with and that it has been provided by a
trusted vendor.
Accordingly, patches, service packs, device drivers, or operating system
components must be signed with a certificate recognized and approved by the
organization.
Verifying the authenticity of the software prior to installation
validates the integrity of the patch or upgrade received from a vendor.
This ensures the software has not been tampered with and that it has been
provided by a trusted vendor. Self-signed certificates are disallowed by
this requirement. Certificates used to verify the software must be from an
approved Certificate Authority (CA).
apt_get should be configured to verify the signature(s) of local packages prior to installation. To configure apt_get to verify signatures of local packages, set the localpkg_gpgcheck to 1 in /etc/apt/apt.conf.
Changes to any software components can have significant effects to the overall security
of the operating system. This requirement ensures the software has not been tampered and
has been provided by a trusted vendor.
Accordingly, patches, service packs, device drivers, or operating system components must
be signed with a certificate recognized and approved by the organization.
Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components of local packages without verification of the repository metadata. Check that apt_get verifies the repository metadata prior to install with the following command. This should be configured by setting repo_gpgcheck to 1 in /etc/apt/apt.conf.
Changes to any software components can have significant effects to the overall security of the operating system. This requirement ensures the software has not been tampered and has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. NOTE: For U.S. Military systems, this requirement does not mandate DoD certificates for this purpose; however, the certificate used to verify the software must be from an approved Certificate Authority.