Apple issued a security update to patch a potential vulnerability within Java affecting Mac OS X 10.4.5.
A specially crafted application could bypass built-in security and allow access to system files by an intruder. The problem is located within Java web Start, which loads Java applications over the internet.
Also, other bugs within the Java runtime that pose a potential security risk were also fixed as part of the update.
Mac OS X is not the only operating system affected by the issues. Windows, Solaris and Linux are also vulnerable. In February, Sun issued an advisory warning of both flaws, and said at the time that no reports of attackers exploiting the issues had been received. To download the updated version click here
For more information read Apple's security report