Amazon Linux 2023 must have GPG signature verification enabled for all software repositories.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
high	V-273998	SRG-OS-000366-GPOS-00153	AZLX-23-000125	SV-273998r1119982_rule	2025-07-15	1

Description
Changes to any software components can have significant effects on the overall security of Amazon Linux 2023. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. All software packages must be signed with a cryptographic key recognized and approved by the organization. Verifying the authenticity of software prior to installation validates the integrity of the software package received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor.

Description

Changes to any software components can have significant effects on the overall security of Amazon Linux 2023. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. All software packages must be signed with a cryptographic key recognized and approved by the organization. Verifying the authenticity of software prior to installation validates the integrity of the software package received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor.

ℹ️ Check
Verify Amazon Linux 2023 software repositories enforce a signature check on the packages prior to allowing installation with the following command: $ grep -w gpgcheck /etc/yum.repos.d/*.repo \| more /etc/yum.repos.d/amazonlinux.repo:gpgcheck=1 /etc/yum.repos.d/amazonlinux.repo:gpgcheck=1 /etc/yum.repos.d/amazonlinux.repo:gpgcheck=1 /etc/yum.repos.d/kernel-livepatch.repo:gpgcheck=1 /etc/yum.repos.d/kernel-livepatch.repo:gpgcheck=1 If any repository has "gpgcheck=0" or "False", or if the option is commented out, this is a finding.

ℹ️ Check

Verify Amazon Linux 2023 software repositories enforce a signature check on the packages prior to allowing installation with the following command: $ grep -w gpgcheck /etc/yum.repos.d/*.repo | more /etc/yum.repos.d/amazonlinux.repo:gpgcheck=1 /etc/yum.repos.d/amazonlinux.repo:gpgcheck=1 /etc/yum.repos.d/amazonlinux.repo:gpgcheck=1 /etc/yum.repos.d/kernel-livepatch.repo:gpgcheck=1 /etc/yum.repos.d/kernel-livepatch.repo:gpgcheck=1 If any repository has "gpgcheck=0" or "False", or if the option is commented out, this is a finding.

✔️ Fix
Configure Amazon Linux 2023 to verify the signature of packages from a repository prior to installation by setting the following option in the "/etc/yum.repos.d/[your_repo_name].repo" file: gpgcheck=1