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.
mod_cluster in JBoss Enterprise Application Platform 5.1.2 for Red Hat Linux allows worker nodes to register with arbitrary virtual hosts, which allows remote attackers to bypass intended access restrictions and provide malicious content, hijack sessions, and steal credentials by registering from an external vhost that does not enforce security constraints.