Session fixation vulnerability in Virtual Hosting Control System (VHCS) 2.4.7.1 and earlier allows remote attackers to hijack web sessions by setting the PHPSESSID parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/35548
http://www.securityfocus.com/bid/25006
http://www.securityfocus.com/archive/1/474324/100/0/threaded
http://www.majorsecurity.de/index_2.php?major_rls=major_rls51