Keycloak-services: keycloak-services: dcr protocol mapper config not validated, allowing iat holders to forge sub and aud claims in signed tokens

Overview

Keycloak provides a Dynamic Client Registration feature that allows users with specific tokens to register their own applications. A flaw in how Keycloak validates these registration requests allows an attacker to create a malicious application that forges identity information. By mapping their own user profile details to protected fields like the user ID (sub) or intended audience (aud), an attacker can generate signed security tokens that make them appear to be a different user. This could allow an attacker to impersonate other users or gain unauthorized access to services that rely on these tokens for identity verification.

Affected

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

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.