wp-admin/includes/post.php in WordPress before 3.6.1 allows remote authenticated users to spoof the authorship of a post by leveraging the Author role and providing a modified user_ID parameter.
http://www.debian.org/security/2013/dsa-2757
http://wordpress.org/news/2013/09/wordpress-3-6-1/
http://lists.fedoraproject.org/pipermail/package-announce/2013-September/117118.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-September/116832.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-September/116828.html