VSNS Lemon 3.2.0 allows remote attackers to bypass authentication and access password-protected articles by setting the vsns[topic_id] cookie to the targeted topic.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25459
http://www.securityfocus.com/bid/17396
http://www.securityfocus.com/archive/1/430345/100/0/threaded
http://securitytracker.com/id?1015836