Apple Leaves Major Java Security Hole Open for Mac Users

A security researcher releases a proof-of-concept exploit making use of a Java flaw affecting Mac OS X. The flaw can be exploited via drive-by attacks to gain control of a vulnerable system. Apple officials say they are working on a fix.

It's time for Apple to close a security hole opened by vulnerable Java applets.

That's the message from security researcher and former Apple engineer Landon Fuller, who posted a proof-of-concept exploit that takes advantage of a Java flaw that was fixed by Sun Microsystems months ago.

The vulnerability, CVE-2008-5353, enables malicious code to escape the Java sandbox and run commands with the permissions of the user. As a result, untrusted Java applets can execute arbitrary code merely by visiting a Web page hosting the applet.

Despite the fact that Sun fixed the issue in January, the vulnerability remains in the JVMs Apple is shipping, as well as in SoyLatte 1.0.3.

"Unfortunately, it seems that many Mac OS X security issues are ignored if the severity of the issue is not adequately demonstrated," Fuller wrote in a blog post May 19. "Due to the fact that an exploit for this issue is available in the wild, and the vulnerability has been public knowledge for six months, I have decided to release... my own proof of concept to demonstrate the issue."

A spokesperson for Apple told eWEEK the company is aware of the problem and is working on a fix.

According to an advisory from Mac security company Intego, the flaw can allow hackers to run code and potentially access or delete files on any Mac, as well as run applications with the rights of the user.

"In addition, if this flaw is executed together with a privilege escalation vulnerability, hackers could remotely run any system-level process and get total access to any Mac," Intego officials stated.

So far, Intego has not found any malicious applets in the wild. To mitigate the issue, "Mac OS X users should disable Java applets in their browsers and disable 'Open 'safe' files after downloading' in Safari," Fuller advised.

"SoyLatte users running untrusted code should upgrade to an OpenJDK6-based release, where possible," as it is not affected by the vulnerability, he added. Since SoyLatte does not provide browser plug-ins, the impact of the vulnerability is limited as well.