A denial of service vulnerability was found in Keycloak that could allow an administrative user with the right to change realm settings to disrupt the service. This action is done by modifying any of the security headers and inserting newlines, which causes the Keycloak server to write to a request that has already been terminated, leading to the failure of said request.

Affected: Maven: org.keycloak:keycloak-quarkus-server

A potential Denial of Service (DoS) vulnerability has been identified in Keycloak, which could allow an administrative user with the rights to change realm settings to disrupt the service. This is done by modifying any of the security headers and inserting newlines, which causes the Keycloak server to write to a request that is already terminated, leading to a failure of said request.

Service disruption may happen, users will be unable to access applications relying on Keycloak, or any of the consoles provided by Keycloak itself on the affected realm.

org.keycloak:keycloak-quarkus-server: Denial of Service in Keycloak Server via Security Headers org.keycloak:keycloak-quarkus-server: Unrestricted admin use of system and environment variables

Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Keycloak ausnutzen, um einen Denial-of-Service-Zustand zu erzeugen oder um vertrauliche Informationen offenzulegen.