Description
WordPress Plugin User Meta is prone to a vulnerability that lets attackers upload arbitrary files. The issue occurs because the application fails to adequately sanitize user-supplied input. An attacker can exploit this vulnerability to upload arbitrary PHP code and run it in the context of the Web server process. This may facilitate unauthorized access or privilege escalation; other attacks are also possible. WordPress Plugin User Meta version 1.1.1 is vulnerable; prior versions may also be affected.
Remediation
Restrict access to the wp-content/plugins/user-meta/framework/helper/uploader.php file (e.g. via .htaccess)
References
http://www.securityfocus.com/bid/53910/exploit
http://www.exploit-db.com/exploits/19052/
http://1337day.com/exploits/18560
http://packetstormsecurity.com/files/113518/WordPress-User-Meta-1.1.1-Shell-Upload.html