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.
http://www.securityfocus.com/bid/72832
http://www.debian.org/security/2015/dsa-3176
http://lists.fedoraproject.org/pipermail/package-announce/2015-March/154047.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/154213.html
http://blog.bestpractical.com/2015/02/security-vulnerabilities-in-rt.html