Title

RHEL 9, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. (Cat II impact)

Discussion

Without path validation, an informed trust decision by the relying party cannot be made when presented with any certificate not already explicitly trusted. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor; it can be, for example, a Certification Authority (CA). A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate, typically issued by a trusted CA. This requirement verifies that a certification path to an accepted trust anchor is used for certificate validation and that the path includes status information. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Status information for certification paths includes certificate revocation lists or online certificate status protocol responses. Validation of the certificate status information is out of scope for this requirement. Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000384-GPOS-00167

Check Content

Verify RHEL 9 for PKI-based authentication has valid certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Check that the system has a valid DoD root CA installed with the following command: $ sudo openssl x509 -text -in /etc/sssd/pki/sssd_auth_ca_db.pem Example output: Certificate: Data: Version: 3 (0x2) Serial Number: 1 (0x1) Signature Algorithm: sha256WithRSAEncryption Issuer: C = US, O = U.S. Government, OU = DoD, OU = PKI, CN = DoD Root CA 3 Validity Not Before: Mar 20 18:46:41 2012 GMT Not After: Dec 30 18:46:41 2029 GMT Subject: C = US, O = U.S. Government, OU = DoD, OU = PKI, CN = DoD Root CA 3 Subject Public Key Info: Public Key Algorithm: rsaEncryption If the root CA file is not a DoD-issued certificate with a valid date and installed in the "/etc/sssd/pki/sssd_auth_ca_db.pem" location, this is a finding.

Fix Text

Configure RHEL 9, for PKI-based authentication, to validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Obtain a valid copy of the DoD root CA file from the PKI CA certificate bundle from cyber.mil and copy the DoD_PKE_CA_chain.pem into the following file: /etc/sssd/pki/sssd_auth_ca_db.pem

Additional Identifiers

Rule ID: SV-258131r926380_rule

Vulnerability ID: V-258131

Group Title: SRG-OS-000066-GPOS-00034

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.