The GenericConsumer class in the Consumer component in ZendOpenId before 2.0.2 and the Zend_OpenId_Consumer class in Zend Framework 1 before 1.12.4 does not verify that the openid_op_endpoint value identifies the same Identity Provider as the provider used in the association handle, which allows remote attackers to bypass authentication and spoof arbitrary OpenID identities by using a malicious OpenID Provider that generates OpenID tokens with arbitrary identifier and claimed_id values.
http://advisories.mageia.org/MGASA-2014-0151.html
http://framework.zend.com/security/advisory/ZF2014-02
http://seclists.org/oss-sec/2014/q2/0
http://www.debian.org/security/2015/dsa-3265
http://www.mandriva.com/security/advisories?name=MDVSA-2014:072