Vulnerability Discussion

Cryptographic verification of vendor software packages ensures that all software packages are obtained from a valid source and protects against spoofing that could lead to installation of malware on the system. Red Hat cryptographically signs all software packages, which includes updates, with a GPG key to verify that they are valid.

Check

Confirm Red Hat package-signing keys are installed on the system and verify their fingerprints match vendor values.

Note: For RHEL 9 software packages, Red Hat uses GPG keys labeled "release key 2" and "auxiliary key 3". The keys are defined in key file "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" by default.

List Red Hat GPG keys installed on the system:

$ sudo rpm -q --queryformat "%{SUMMARY}\n" gpg-pubkey | grep -i "red hat"

Red Hat, Inc. (release key 2) <[email protected]> public key
Red Hat, Inc. (auxiliary key 3) <[email protected]> public key

If Red Hat GPG keys "release key 2" and "auxiliary key 3" are not installed, this is a finding.

List key fingerprints of installed Red Hat GPG keys:

$ sudo gpg -q --keyid-format short --with-fingerprint /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

If key file "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" is missing, this is a finding.

Example output:

pub rsa4096/FD431D51 2009-10-22 [SC]
Key fingerprint = 567E 347A D004 4ADE 55BA 8A5F 199E 2F91 FD43 1D51
uid Red Hat, Inc. (release key 2) <[email protected]>
pub rsa4096/5A6340B3 2022-03-09 [SC]
Key fingerprint = 7E46 2425 8C40 6535 D56D 6F13 5054 E4A4 5A63 40B3
uid Red Hat, Inc. (auxiliary key 3) <[email protected]>

Compare key fingerprints of installed Red Hat GPG keys with fingerprints listed for RHEL 9 on Red Hat "Product Signing Keys" webpage at https://access.redhat.com/security/team/key.

If key fingerprints do not match, this is a finding.

Fix

Install Red Hat package-signing keys on the system and verify their fingerprints match vendor values.

Insert RHEL 9 installation disc or attach RHEL 9 installation image to the system. Mount the disc or image to make the contents accessible inside the system.

Assuming the mounted location is "/media/cdrom", use the following command to copy Red Hat GPG key file onto the system:

$ sudo cp /media/cdrom/RPM-GPG-KEY-redhat-release /etc/pki/rpm-gpg/

Import Red Hat GPG keys from key file into system keyring:

$ sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

Using the steps listed in the Check Text, confirm the newly imported keys show as installed on the system and verify their fingerprints match vendor values.