The email gateway in RT (aka Request Tracker) 3.0.0 through 4.x before 4.0.23 and 4.2.x before 4.2.10 allows remote attackers to cause a denial of service (CPU and disk consumption) via a crafted email.
Debian Linux Security Advisory 3176-1 - Multiple vulnerabilities have been discovered in Request Tracker, an extensible trouble-ticket tracking system.