CRLF injection vulnerability in Request Tracker (RT) 3.8.x before 3.8.17 and 4.0.x before 4.0.13 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a MIME header.
http://www.debian.org/security/2012/dsa-2670
http://secunia.com/advisories/53522
http://secunia.com/advisories/53505
http://lists.bestpractical.com/pipermail/rt-announce/2013-May/000228.html
http://lists.bestpractical.com/pipermail/rt-announce/2013-May/000227.html
http://lists.bestpractical.com/pipermail/rt-announce/2013-May/000226.html