A bug exists in Keycloak 7.x where the user federation LDAP bind type is "none" (LDAP anonymous bind), any password, invalid or valid will be accepted
Mitigation: If the LDAP service supports "simple" use that method instead
A vulnerability was found in keycloak 7.x, when keycloak is configured with LDAP user federation and StartTLS is used instead of SSL/TLS from the LDAP server (ldaps), in this case user authentication succeeds even if invalid password has entered.