OpenID allows remote attackers to forcibly log a user into an OpenID enabled site, divulge the user’s personal information to this site, and add it site to the trusted sites list via a crafted web page, related to cached tokens.
janrain.com/blog/2007/03/22/myopenid-security-fix/
openid.net/pipermail/security/2007-March/000286.html
openid.net/pipermail/security/2007-March/000288.html
openid.net/pipermail/security/2007-March/000291.html
openid.net/pipermail/security/2007-March/000306.html
openid.net/pipermail/security/2007-March/000311.html
osvdb.org/43601