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Java 7 Applet Remote Code Execution

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Java 7 Applet Remote Code Execution

Disclosed
08/26/2012
Created
05/30/2018

Description

The exploit takes advantage of two issues in JDK 7: The ClassFinder and MethodFinder.findMethod(). Both were newly introduced in JDK 7. ClassFinder is a replacement for classForName back in JDK 6. It allows untrusted code to obtain a reference and have access to a restricted package in JDK 7, which can be used to abuse sun.awt.SunToolkit (a restricted package). With sun.awt.SunToolkit, we can actually invoke getField() by abusing findMethod() in Statement.invokeInternal() (but getField() must be public, and that's not always the case in JDK 6) in order to access Statement.acc's private field, modify AccessControlContext, and then disable Security Manager. Once Security Manager is disabled, we can execute arbitrary Java code. Our exploit has been tested successfully against multiple platforms, including: IE, Firefox, Safari, Chrome; Windows, Ubuntu, OS X, Solaris, etc.

Author(s)

  • Adam Gowdiak
  • James Forshaw
  • jduck <jduck@metasploit.com>
  • sinn3r <sinn3r@metasploit.com>
  • juan vazquez <juan.vazquez@metasploit.com>

Platform

Java,Linux,Windows

Development

References

Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':

msf > use exploit/multi/browser/java_jre17_exec
msf exploit(java_jre17_exec) > show targets
    ...targets...
msf exploit(java_jre17_exec) > set TARGET < target-id >
msf exploit(java_jre17_exec) > show options
    ...show and set options...
msf exploit(java_jre17_exec) > exploit

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– Jim O’Gorman | President, Offensive Security

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