Collabtive 0.4.8 allows remote attackers to bypass authentication and create new users, including administrators, via unspecified vectors associated with the added mode in a users action to admin.php.
https://www.exploit-db.com/exploits/7076
https://exchange.xforce.ibmcloud.com/vulnerabilities/46497
http://www.securityfocus.com/bid/32229
http://www.securityfocus.com/archive/1/498186/100/0/threaded