SQL injection vulnerability in xmlrpc (xmlrpc.php) in WordPress 2.1.2, and probably earlier, allows remote authenticated users to execute arbitrary SQL commands via a string parameter value in an XML RPC mt.setPostCategories method call, related to the post_id variable.
https://www.exploit-db.com/exploits/3656
http://www.vupen.com/english/advisories/2007/1245
http://www.debian.org/security/2007/dsa-1285
http://trac.wordpress.org/ticket/4091