exiftags before 1.01 allows attackers to cause a denial of service (infinite loop) via recursive IFD references in the EXIF data in a JPEG image.
http://www.vupen.com/english/advisories/2007/4251
http://www.securityfocus.com/bid/26892
http://www.debian.org/security/2008/dsa-1533
http://security.gentoo.org/glsa/glsa-200712-17.xml
http://secunia.com/advisories/29580
http://secunia.com/advisories/28268
http://secunia.com/advisories/28110