‘Sun Java Runtime Environment Trusted Methods Chaining Code Execution Vulnerability’

Summary

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Sun Java Runtime.’

Credit:

‘The information has been provided by Sami Koivu.
The original article can be found at: http://www.zerodayinitiative.com/advisories/ZDI-10-056/


Details

Vulnerable Systems:
 * Sun Microsystems Java Runtime Environment (JRE)

Authentication is not required to exploit this vulnerability.

The specific flaw exists within the code responsible for ensuring proper privileged execution of methods. If an untrusted method in an applet attempts to call a method that requires privileges, Java will walk the call stack and for each entry verify that the method called is defined within a class that has that privilege. However, this does not take into account an untrusted object that has extended the trusted class without overwriting the target method. Additionally, this can be bypassed by abusing a similar trust issue with interfaces. An attacker can leverage these insecurities to execute vulnerable code under the context of the user invoking the JRE.

Patch Availability:
Sun Microsystems has issued an update to correct this vulnerability. More details can be found at:
http://www.oracle.com/technology/deploy/security/critical-patch-updates/javacpumar2010.html

CVE Information:
CVE-2010-0840

Disclosure Timeline:
2009-11-24 – Vulnerability reported to vendor
2010-04-05 – Coordinated public release of advisory’

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