The TIFFYCbCrtoRGB function in LibTIFF 3.9.0 and 3.9.2, as used in ImageMagick, does not properly handle invalid ReferenceBlackWhite values, which allows remote attackers to cause a denial of service (application crash) via a crafted TIFF image that triggers an array index error, related to "downsampled OJPEG input."
http://marc.info/?l=oss-security&m=127731610612908&w=2
https://bugzilla.redhat.com/show_bug.cgi?id=583081
http://secunia.com/advisories/40422
http://secunia.com/advisories/40527
http://secunia.com/advisories/50726
http://security.gentoo.org/glsa/glsa-201209-02.xml
http://www.debian.org/security/2012/dsa-2552