SysAid Help Desk before 15.2 allows remote attackers to cause a denial of service (CPU and memory consumption) via a large number of nested entity references in an XML document to (1) /agententry, (2) /rdsmonitoringresponse, or (3) /androidactions, aka an XML Entity Expansion (XEE) attack.
https://www.sysaid.com/blog/entry/sysaid-15-2-your-voice-your-service-desk
http://www.securityfocus.com/bid/75038
http://www.securityfocus.com/archive/1/535679/100/0/threaded