A flaw was found in Keycloak. Keycloak's Security Assertion Markup Language (SAML) broker endpoint does not properly validate encrypted assertions when the overall SAML response is not signed. An attacker with a valid signed SAML assertion can exploit this by crafting a malicious SAML response. This allows the attacker to inject an encrypted assertion for an arbitrary principal, leading to unauthorized access and potential information disclosure.
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.