Summary:

When organizationsEnabled is set to false at the realm level, Keycloak
correctly blocks the admin Organizations API (returning 404), but
fails to enforce the disabled state on user-facing paths. The account
API (GET /realms/{realm}/account/organizations) continues to return
organization membership data, and OIDC token requests with
scope=openid organization still issue tokens containing the
organization claim. This allows organization metadata to leak into
tokens that resource servers may use for authorization decisions, even
after an administrator has explicitly disabled the Organizations
feature.

Requirements to exploit:

The attacker must be an authenticated user with existing organization
membership. The realm must have had Organizations enabled previously
and then disabled by an administrator. The client must be configured
to allow the organization scope. The exploit is confirmed for
client-credentials and resource-owner-password grant types, and the
account API.

Component affected: org.keycloak.organization

Version affected: Versions with Organizations support (reported via
YWH, specific version not stated)

Patch available: no

CVSS: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N (4.3 Medium)

Embargo: no

Acknowledgement:

Name: Evan Hendra
Affiliation: Independent Security Researcher
Email: evanhendra48

Steps to reproduce:

1. Enable Organizations on a realm and create organization memberships
for users.
2. As an administrator, disable Organizations by setting
organizationsEnabled=false on the realm.
3. As an authenticated user, send GET
/realms/{realm}/account/organizations. Observe that organization
membership data is returned (200 OK) despite the feature being
disabled.
4. Request a token with scope=openid organization using the
client-credentials or resource-owner-password grant type. Observe that
the issued token contains the organization claim.
5. A resource server relying on the organization claim will continue
applying organization-based authorization even though the
administrator disabled the feature.