Zeacom Chat Server before 5.1 uses too short a random string for the JSESSIONID value, which makes it easier for remote attackers to hijack sessions or cause a denial of service (Chat Server crash or Tomcat daemon crash) via a brute-force attack.
https://exchange.xforce.ibmcloud.com/vulnerabilities/67540
http://www.securityfocus.com/bid/47910
http://www.securityfocus.com/archive/1/518037/100/0/threaded