xmlrpc (xmlrpc.php) in WordPress 2.1.2, and probably earlier, allows remote authenticated users with the contributor role to bypass intended access restrictions and invoke the publish_posts functionality, which can be used to "publish a previously saved post."
https://exchange.xforce.ibmcloud.com/vulnerabilities/33470
http://www.vupen.com/english/advisories/2007/1245
http://www.notsosecure.com/folder2/2007/04/03/wordpress-212-xmlrpc-security-issues/
http://www.debian.org/security/2007/dsa-1285
http://trac.wordpress.org/ticket/4091