Stack-based buffer overflow in Apple Type Services (ATS) in Apple Mac OS X 10.5.8 and 10.6.4 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted embedded font in a document.
http://support.apple.com/kb/HT4312
http://securitytracker.com/id?1024359
http://lists.apple.com/archives/security-announce/2010//Aug/msg00003.html