Vulnerability Note VU#760344

Sun Java Plug-in fails to restrict access to private Java packages

Java's built-in security framework is designed to prevent access to private Java packages that are used internally by the Java Virtual Machine (JVM). When a Java applet attempts to access one of these packages, an AccessControlException will be thrown indicating that the requested access is denied. However, a flaw in the security framework fails to prevent such access to these private Java packages via JavaScript code.

II. Impact

The reporter notes that some private Java packages contain classes that allow direct access to memory or provide methods that can modify private fields of Java objects. This could allow an intruder to disable the Java security manager.

III. Solution

Sun has issued an advisory which addresses this issue. For more information on upgrades available for your system, please refer to Sun Security Alert 57591.

Systems Affected

http://jouko.iki.fi/adv/javaplugin.html
http://www.idefense.com/application/poi/display?id=158&type=vulnerabilities&flashstatus=false
http://secunia.com/advisories/13271/
http://sunsolve.sun.com/search/document.do?assetkey=1-26-57591-1
http://java.sun.com/products/plugin/index.jsp
http://java.sun.com/j2se/desktopjava/jre/index.jsp
http://java.sun.com/docs/books/tutorial/essential/system/securityIntro.html
http://java.sun.com/j2se/1.5.0/docs/api/java/security/AccessControlException.html
http://java.sun.com/docs/books/tutorial/reflect/

Credit

This vulnerability was reported by Jouko Pynnonen.

This document was written by Damon Morda.

Other Information

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