Launchpad.net

CVE 2010-3685

The OpenID module in Drupal 6.x before 6.18, and the OpenID module 5.x before 5.x-1.4 for Drupal, violates the OpenID 2.0 protocol by not checking for reuse of openid.response_nonce values, which allows remote attackers to bypass authentication by leveraging an assertion from an OpenID provider.

See the CVE page on Mitre.org for more details.