FreeType in CoreGraphics in Apple iOS before 5.0.1 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted font in a document.
lists.apple.com/archives/Security-announce/2011/Nov/msg00001.html
lists.opensuse.org/opensuse-security-announce/2011-12/msg00008.html
lists.opensuse.org/opensuse-security-announce/2012-01/msg00003.html
lists.opensuse.org/opensuse-security-announce/2012-01/msg00012.html
secunia.com/advisories/46921
secunia.com/advisories/48951
support.apple.com/kb/HT5052