adduser.php in PHP-AGTC Membership (AGTC-Membership) System 1.1a does not require authentication, which allows remote attackers to create accounts via a modified form, as demonstrated by an account with admin (userlevel 4) privileges.
https://exchange.xforce.ibmcloud.com/vulnerabilities/38173
http://www.securityfocus.com/bid/26255
http://www.securityfocus.com/archive/1/482919/100/0/threaded