The HipChat for JIRA plugin before 6.30.0 for Atlassian JIRA allows remote authenticated users to execute arbitrary Java code via unspecified vectors, related to "Velocity Template Injection Vulnerability."
https://www.exploit-db.com/exploits/38905/
https://www.exploit-db.com/exploits/38551/
http://www.securityfocus.com/archive/1/536374/100/0/threaded
http://packetstormsecurity.com/files/133401/Jira-HipChat-For-Jira-Java-Code-Execution.html