Friday, January 18, 2013

Java Zero Day Vulnerability Exploits JMX and MethodHandles

I recently identified software security issues (#2), especially related to Java, as one of the most significant software development themes of 2012. Not even a month into 2013, a news story receiving a lot of press is the U.S. Department of Homeland Security's issuing of Alert (TA13-010A), which is described with more technical details in Vulnerability Note VU#625617. Oracle has since released a Security Alert for CVE-2013-0422.

Vulnerability Note VU#625617 includes a paragraph that is particularly insightful:

By leveraging the a vulnerability in the Java Management Extensions (JMX) MBean components, unprivileged Java code can access restricted classes. By using that vulnerability in conjunction with a second vulnerability involving recursive use of the Reflection API via the invokeWithArguments method of the MethodHandle class, an untrusted Java applet can escalate its privileges by calling the the setSecurityManager() function to allow full privileges, without requiring code signing. Oracle Java 7 update 10 and earlier Java 7 versions are affected. OpenJDK 7, and subsequently IcedTea, are also affected. The invokeWithArguments method was introduced with Java 7, so therefore Java 6 is not affected.

The above scenario is described in great detail in Tim Boudreau's excellent The Java Security Exploit in (Mostly) Plain English and he references Java 0day 1.7.0_10 decrypted source code that demonstrates the code that can implement an attack that takes advantage of the described JMX/MethodHandles combination vulnerability. Kafeine's (Malware don't need Coffee) post 0 day 1.7u10 (CVE-2013-0422) spotted in the Wild - Disable Java Plugin NOW ! provides numerous screen snapshots to illustrate this Java Zero-Day Malware in action.

The TA13-010A/CVE-2013-0422 Java Zero Day Vulnerability has made the mainstream news with coverage by Norton/Symantec (What's All the Buzz About Java? Fixing The Vulnerability and Java Zero-Day Dished Up from Cool Exploit Kit), McAfee (Java Zero-Day Vulnerability Pushes Out Crimeware), InformationWeek (Java Zero Day Attack: Second Bug Found), Fox News (Reuters: As Hacking Concerns Build, U.S. Warns on Java Software), CNN (Critical Java vulnerability due to incomplete earlier patch), and many more news outlets.

As stated above, Oracle has issued a patch, but the Department of Homeland Security still recommends disabling Java in the browser.

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