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Sun Java Runtime Environment "reflection" API privilege elevation vulnerabilities

Vulnerability Note VU#974188

Original Release Date: 2005-12-02 | Last Revised: 2006-01-13


Multiple vulnerabilities in the Sun Java Reflection API may allow an untrusted Java applet to bypass security restrictions and execute arbitrary code.


The Sun Java Reflection API allows Java classes to determine information about other Java classes, such as public methods. There are three, unspecified vulnerabilities in the Reflection API that may allow a Java applet to bypass Java applet security restrictions. Once the security restrictions are bypassed, the malicious applet may be able to access and manipulate system resources.

For more information on the Java security model see Sun's Java documentation, particularly the Applet Security FAQ. For more information regarding these vulnerabilities and how to correct them, please refer to Sun Alert 102003.


By convincing a user to run a Java applet, a remote, unauthenticated attacker may be able to execute arbitrary code with the privileges of the user running the applet. Web browsers with Java support may run applets from untrusted web sites.


Upgrade Java
Sun has released two separate updates to correct these issues. Sun Alert 102003 describes the following patches:

The first issue is addressed in the following releases:

      • SDK and JRE 1.3.1_16 and later
      • SDK and JRE 1.4.2_09 and later
      • JDK and JRE 5.0 Update 4 and later
The second and third issues are addressed in the following releases:

      • SDK and JRE 1.4.2_09 and later
      • JDK and JRE 5.0 Update 4 and later
J2SE 1.4.2 is available for download at

J2SE 5.0 is available for download at

and at

Note: It is recommended that affected versions be removed from your system. For more information, please see the installation notes on the respective download pages.

Do not access Java Applets from untrusted sources

Attackers must deliver a malicious Java applet to a vulnerable system in order to take advantage of this vulnerability. By only accessing Java applets from known and trusted sources the chances of exploitation are reduced.

Disable Java in web browser

Java applets are commonly executed within a web browser. Disabling Java within the web browser may prevent an attacker from delivering a malicious applet to a vulnerable system.

Vendor Information


Sun Microsystems, Inc. Affected

Notified:  November 29, 2005 Updated: November 29, 2005



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


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These vulnerabilities were reported by Sun Microsystems. Sun credits Adam Gowdiak, with providing information regarding these issues.

This document was written by Jeff Gennari.

Other Information

CVE IDs: CVE-2005-3906
Severity Metric: 26.33
Date Public: 2005-11-28
Date First Published: 2005-12-02
Date Last Updated: 2006-01-13 21:57 UTC
Document Revision: 59

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