As noted by ZDNet, a major security vulnerability in Java 7 has been discovered, with the vulnerability currently being exploited in the wild by malicious parties. In response to threat, the U.S. Department of Homeland Security has recommended that users disable the Java 7 browser plug-in entirely until a patch is made available by Oracle.

Hackers have discovered a weakness in Java 7 security that could allow the installation of malicious software and malware on machines that could increase the chance of identity theft, or the unauthorized participation in a botnet that could bring down networks or be used to carry out denial-of-service attacks against Web sites. "We are currently unaware of a practical solution to this problem," said the DHS' Computer Emergency Readiness Team (CERT) in a post on its Web site on Thursday evening. "This vulnerability is being attacked in the wild, and is reported to be incorporated into exploit kits. Exploit code for this vulnerability is also publicly available."

Apple has, however, apparently already moved quickly to address the issue, disabling the Java 7 plug-in on Macs where it is already installed. Apple has achieved this by updating its "Xprotect.plist" blacklist to require a minimum of an as-yet unreleased 1.7.0_10-b19 version of Java 7. With the current publicly-available version of Java 7 being 1.7.0_10-b18, all systems running Java 7 are failing to pass the check initiated through the anti-malware system built into OS X.



Apple's updated plug-in blacklist requiring an unreleased version of Java 7

Apple historically provided its own support for Java on OS X, but in October 2010 began pushing support for Java back to Oracle, with Steve Jobs noting that the previous arrangement resulted in Apple's Java always being a version behind that available to other platforms through Oracle. Consequently, Jobs acknowledged that having Apple responsible for Java "may not be the best way to do it."

It wasn't until last August that the transition was essentially complete, with Oracle officially launching Java 7 for OS X. Java 7 does not ship by default on Mac systems, meaning that many users are not affected this latest issue or other recent ones, but those users who have manually installed Java 7 may be experiencing issues with their systems.

There is no word yet on when an updated version of Java addressing the issue will be made available by Oracle.

Update: As detailed in the National Vulnerability Database, the issue affects not only the Java 7 plug-in, but at least some versions of Java 4 through 7.