CoreText in Apple Mac OS X before 10.6.7 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a document that contains a crafted embedded font.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2011-0205
http://support.apple.com/kb/HT4581
http://lists.apple.com/archives/security-announce/2011/Mar/msg00006.html