Programmer and former Apple engineer Landon Fuller has released a proof-of-concept exploit demonstrating vulnerabilities in Apple's current implementation of Java that allow arbitrary code execution in Java-enabled Web browsers. While the vulnerabilities, first discovered last August, were disclosed and patched by Sun last December, Apple has yet to roll out a fix for its own implementation of Java.
CVE-2008-5353 allows malicious code to escape the Java sandbox and run arbitrary commands with the permissions of the executing user. This may result in untrusted Java applets executing arbitrary code merely by visiting a web page hosting the applet. The issue is trivially exploitable.
Unfortunately, these vulnerabilities remain in Apple's shipping JVMs, as well as Soylatte 1.0.3. As Soylatte does not provide browser plugins, the impact of the vulnerability is reduced. The recent release of OpenJDK6/Mac OS X is not affected by CVE-2008-5353.
With the recent release of OS X 10.5.7 failing to address the vulnerabilities, Fuller decided to create and release his proof-of-concept exploit in order to bring attention to the severity of the issue. The proof-of-concept exploit uses a browser-based Java applet to activate the Unix "say" command on the user's system and recite a statement regarding the exploit initiating an innocuous process.
The only recommended workaround at this time is to disable Java applets in all browsers and to disable the 'Open "safe" files after downloading' option in Safari. Disabling Java applets will cause some websites to behave incorrectly, but no other protection against exploits of the vulnerabilities is available until Apple releases a patch.
