CVE-2019-14910

A flaw was found in keycloak 7.x where an invalid password is accepted for user authentication when LDAP user federation and STARTTLS is used instead of SSL/TLS from the LDAP server. This can allow an attacker to log into a system using any entry for a password authentication and still gain access to the system.

Mitigation

Disabling STARTTLS will fix the authentication flaw but leave the connection to the LDAP server unencrypted. Utilizing LDAPS will add a layer of encryption back to the LDAP connection but only at the SSLv3 level which also poses problems in and of itself.