Buffer overflow in International Components for Unicode (ICU) in Apple Mac OS X before 10.6.8 allows context-dependent attackers to execute arbitrary code or cause a denial of service (application crash) via vectors involving uppercase strings.
https://exchange.xforce.ibmcloud.com/vulnerabilities/68217
http://support.apple.com/kb/HT4999
http://support.apple.com/kb/HT4808
http://support.apple.com/kb/HT4723
http://lists.apple.com/archives/security-announce/2011//Jun/msg00000.html
http://lists.apple.com/archives/security-announce/2011//Jul/msg00002.html
http://lists.apple.com/archives/Security-announce/2011//Oct/msg00001.html