New Java zero-day exploit could spread "mayhem"

Researchers at a threat and vulnerability management firm said Thursday morning that they have been able to replicate an exploit taking advantage of a fresh zero-day vulnerability in Java.

"With the files we were able to obtain, we reproduced the exploit in a fully patched new installation of Java," wrote Jaime Blasco, the labs manager at AlienVault.

A researcher known as Kafeine was among the first to spot the zero-day in the wild, deciding it was necessary to go public with the details because the exploit could "cause mayhem."

According to Blasco, the vulnerability resembles another Java flaw (CVE-2012-4681) that was widely exploited in late summer before Oracle, which maintains Java, issued a rare out-of-band patch. 

"The Java file is highly obfuscated, but based on the quick analysis we did, the exploit is probably bypassing certain security checks, tricking the permissions of certain Java classes as we saw in CVE-2012-4681," Blasco wrote. "Right now, the only way to protect your machine against this exploit is disabling the Java browser plug-in. Let's see how long it takes for Oracle to release a patch."

Another emergency fix may be necessary, considering the vulnerability's reach and effectiveness is about to exponentially increase now that it's been added to the commercially available BlackHole and Nuclear Pack exploit kits.

Java has been hard hit in recent years and represents arguably the most common attack vector, prompting a number of security experts to advise users to simply remove the software for good.

"My personal opinion is that Java in the browser is mostly useless these days and should not be used unless really needed," Michael Schierl, a German software developer, told SCMagazine.com in August. "Most things that Java applets used to do can be done with HTML5 [markup language] nowadays or, if needed, with SVG (Scalable Vector Graphics) or Flash. While Flash has its security problems too, the attack surface of Flash is a lot smaller and it is a lot harder to build a reliable exploit for Flash vulnerabilities."