examples/consumer/common.php in JanRain PHP OpenID library (aka php-openid) improperly checks the openid.realm parameter against the SERVER_NAME element in the SERVER superglobal array, which might allow remote attackers to hijack the authentication of arbitrary users via vectors involving a crafted HTTP Host header.

Zend Framework 1 (ZF1) before 1.12.4, Zend Framework 2 before 2.1.6 and 2.2.x before 2.2.6, ZendOpenId, ZendRest, ZendService_AudioScrobbler, ZendService_Nirvanix, ZendService_SlideShare, ZendService_Technorati, and ZendService_WindowsAzure before 2.0.2, ZendService_Amazon before 2.0.3, and ZendService_Api before 1.0.0 allow remote attackers to read arbitrary files, send HTTP requests to intranet servers, and possibly cause a denial of service (CPU and memory consumption) via an XML External Entity (XXE) attack. NOTE: this issue exists because of an incomplete fix for CVE-2012-5657.

Zend Framework 1 (ZF1) before 1.12.4, Zend Framework 2 before 2.1.6 and 2.2.x before 2.2.6, ZendOpenId, ZendRest, ZendService_AudioScrobbler, ZendService_Nirvanix, ZendService_SlideShare, ZendService_Technorati, and ZendService_WindowsAzure before 2.0.2, ZendService_Amazon before 2.0.3, and ZendService_Api before 1.0.0, when PHP-FPM is used, does not properly share the libxml_disable_entity_loader setting between threads, which might allow remote attackers to conduct XML External Entity (XXE) attacks via an XML external entity declaration in conjunction with an entity reference. NOTE: this issue exists because of an incomplete fix for CVE-2012-5657.

Zend Framework 1 (ZF1) before 1.12.4, Zend Framework 2 before 2.1.6 and 2.2.x before 2.2.6, ZendOpenId, ZendRest, ZendService_AudioScrobbler, ZendService_Nirvanix, ZendService_SlideShare, ZendService_Technorati, and ZendService_WindowsAzure before 2.0.2, ZendService_Amazon before 2.0.3, and ZendService_Api before 1.0.0 allow remote attackers to cause a denial of service (CPU consumption) via (1) recursive or (2) circular references in an XML entity definition in an XML DOCTYPE declaration, aka an XML Entity Expansion (XEE) attack. NOTE: this issue exists because of an incomplete fix for CVE-2012-6532.

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.

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 violate the OpenID 2.0 protocol by ensuring only that at least one field is signed, which allows remote attackers to bypass authentication by leveraging an assertion from an OpenID provider.

The ruby-openid gem before 2.2.2 for Ruby allows remote OpenID providers to cause a denial of service (CPU consumption) via (1) a large XRDS document or (2) an XML Entity Expansion (XEE) attack.

Auth/Yadis/XML.php in PHP OpenID Library 2.2.2 and earlier allows remote attackers to read arbitrary files, send HTTP requests to intranet servers, or cause a denial of service (CPU and memory consumption) via XRDS data containing an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.

mod_auth_openid before 0.7 for Apache uses world-readable permissions for /tmp/mod_auth_openid.db, which allows local users to obtain session ids.

message/ax/AxMessage.java in OpenID4Java before 0.9.6 final, as used in JBoss Enterprise Application Platform 5.1 before 5.1.2, Step2, Kay Framework before 1.0.2, and possibly other products does not verify that Attribute Exchange (AX) information is signed, which allows remote attackers to modify potentially sensitive AX information without detection via a man-in-the-middle (MITM) attack.