Cross-site scripting (XSS) vulnerability in the Admin Control Panel (ACP) in MyBB (aka MyBulletinBoard) before 1.6.7 allows remote administrators to inject arbitrary web script or HTML via a malformed file name in an orphaned attachment.
http://www.securityfocus.com/bid/53417
http://www.openwall.com/lists/oss-security/2012/05/07/14
http://www.openwall.com/lists/oss-security/2012/05/07/13
http://blog.mybb.com/2012/04/01/mybb-1-6-7-update-1-8-development/