Description
A flaw was found in keycloak, where the default ECP binding flow allows other authentication flows to be bypassed. By exploiting this behavior, an attacker can bypass the MFA authentication by sending a SOAP request with an AuthnRequest and Authorization header with the user's credentials. The highest threat from this vulnerability is to confidentiality and integrity.
Remediation
References
https://github.com/keycloak/keycloak/commit/44000caaf5051d7f218d1ad79573bd3d175cad0d
https://bugzilla.redhat.com/show_bug.cgi?id=2007512
https://access.redhat.com/security/cve/CVE-2021-3827
https://github.com/keycloak/keycloak/security/advisories/GHSA-4pc7-vqv5-5r3v