The Hash-based Message Authentication Code (HMAC) provider in Java on Apple Mac OS X 10.4.11, 10.5.4, and 10.5.5 uses an uninitialized variable, which allows remote attackers to execute arbitrary code via a crafted applet, related to an "error checking issue."
https://exchange.xforce.ibmcloud.com/vulnerabilities/45396
http://support.apple.com/kb/HT3179
http://support.apple.com/kb/HT3178
http://lists.apple.com/archives/security-announce//2008/Sep/msg00008.html
http://lists.apple.com/archives/security-announce//2008/Sep/msg00007.html