A flaw was found in Keycloaks Client Policies, specifically within the org.keycloak.protocol.oidc component. When certain condition providers (client-type, client-roles, client-attributes, client-scopes) are used to enforce security restrictions, the reject-ropc-grant executor is silently bypassed. This allows an unauthenticated remote attacker to obtain tokens via a Resource Owner Password Credentials (ROPC) grant, even when a policy is explicitly configured to block it. This bypass can lead to unauthorized access and information disclosure.
Weakness
The product does not handle or incorrectly handles when it has insufficient privileges to access resources or functionality as specified by their permissions. This may cause it to follow unexpected code paths that may leave the product in an invalid state.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Build_of_keycloak | Redhat | - (including) | - (including) |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-operator-bundle:26.4.13-1 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9:26.4-19 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9-operator:26.4-19 | * |
| Red Hat build of Keycloak 26.4.13 | RedHat | rhbk/keycloak-rhel9 | * |
| Red Hat build of Keycloak 26.6 | RedHat | rhbk/keycloak-operator-bundle:26.6.3-3 | * |
| Red Hat build of Keycloak 26.6 | RedHat | rhbk/keycloak-rhel9:26.6-6 | * |
| Red Hat build of Keycloak 26.6 | RedHat | rhbk/keycloak-rhel9-operator:26.6-6 | * |
| Red Hat build of Keycloak 26.6.3 | RedHat | rhbk/keycloak-rhel9 | * |
Potential Mitigations
- Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
- Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.