ZDI-10-056: Sun Java Runtime Environment Trusted Methods Chaining Remote Code Execution Vulnerability
http://www.zerodayinitiative.com/advisories/ZDI-10-056
April 5, 2010

-- CVE ID:
CVE-2010-0840

-- Affected Vendors:
Sun Microsystems

-- Affected Products:
Sun Microsystems Java Runtime

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Sun Java Runtime. 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.

-- Vendor Response:
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

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

-- Credit:
This vulnerability was discovered by:
    * Sami Koivu

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