Multiple vulnerabilities have been reported and acknowledged in Java for Mac OS X, which can be exploited by malicious people to bypass certain security restrictions, disclose sensitive information, cause a DoS (Denial of service), or to compromise a user's system.

1) A vulnerability is caused due to an error in the deserialisation of Calendar objects in Java for Mac OS X. This can be exploited to escape the Java sandbox and execute arbitrary code e.g. when a user visits a web page containing a specially crafted Java applet.

This is related to vulnerability #14 in:
SA32991

This vulnerability is confirmed in Mac OS X 10.5.7. Other versions may also be affected.

2) An input validation error in the "apple.laf.CColourUIResource()" constructor can be exploited by an untrusted Java applet to execute arbitrary code with escalated privileges e.g. when a user visits a specially crafted web site.

This vulnerability is reported in Mac OS X 10.5.7 and later, and Mac OS X Server 10.5.7 and later.

3) Some vulnerabilities in Java can be exploited by malicious people to bypass certain security restrictions, disclose sensitive information, cause a DoS (Denial of service), or compromise a vulnerable system.

For more information:
SA32991
SA34451

Solution
Update to the latest versions.
Further details available to Secunia VIM customers

Provided and/or discovered by
1) Additional information about Java for Mac OS X being affected provided by Landon Fuller and Julien Tinnes.
2) An anonymous researcher, reported via ZDI.

Changelog
Further details available to Secunia VIM customers

Original Advisory
Apple:
http://support.apple.com/kb/HT3632
http://support.apple.com/kb/HT3633

Landon Fuller:
http://landonf.bikemonkey.org/code/macosx/CVE-2008-5353.20090519.html

Julien Tinnes:
http://blog.cr0.org/2009/05/write-once-own-everyone.html

ZDI:
http://www.zerodayinitiative.com/advisories/ZDI-09-043/

Other references
Further details available to Secunia VIM customers

Deep Links
Links available to Secunia VIM customers