Keycloak-services: keycloak-services: saml broker accepts holder-of-key assertions without proof of key possession

Overview

A flaw was found in the SAML identity broker component of Keycloak, which is used to delegate authentication to external identity providers. The issue occurs because the broker fails to verify that a user actually possesses the private key associated with a holder-of-key assertion. An attacker who intercepts a victim signed assertion can replay it to gain unauthorized access and impersonate the victim without needing their private key.

Affected

• keycloak/rhbk-openshift-rhel9 (all versions)
• keycloak-services (all versions)
• rhbk/keycloak-rhel9 (all versions)
• keycloak-services (all versions)

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Workarounds

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.