Keycloak-services: keycloak-services: oidc logout endpoint session fixation via id_token_hint leading to account takeover

Overview

A flaw was found in the OIDC logout endpoint of the keycloak-services component, which handles user session termination in Red Hat Build of Keycloak. The issue occurs because the system sets a session cookie based on an unvalidated token hint before completing security checks. An attacker can use this flaw to fix a session ID in a victim's browser, allowing them to hijack the victim's subsequent login and gain full control over their account.

Affected

• 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.