QuickTime in Apple Mac OS X before 10.6.3 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted movie file with H.264 encoding.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6783
http://support.apple.com/kb/HT4077
http://lists.apple.com/archives/security-announce/2010//Mar/msg00002.html
http://lists.apple.com/archives/security-announce/2010//Mar/msg00001.html