What happened
Keycloak allows users to log in using Google accounts and can be configured to only allow users from specific Google Workspace domains. A flaw was found where the token exchange feature, which allows swapping a Google token for a Keycloak token, does not check these domain restrictions. This means an attacker with a valid Google account from a different domain could bypass the security check and gain access to the Keycloak realm.
Affected versions
Red Hat build of Keycloak 26.6: See vendor advisory Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.