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Mozilla products fail to properly validate JavaScript constructors

Vulnerability Note VU#687396

Original Release Date: 2006-07-27 | Last Revised: 2007-02-09


Mozilla products fail to properly validate references returned by JavaScript constructors. This vulnerability may allow a remote attacker to execute arbitrary code on a vulnerable system.


According to Mozilla Foundation Security Advisory 2006-51:

JavaScript functions have a parent object created using the standard Object() constructor (ECMA-specified behavior) and that this constructor can be redefined by script (also ECMA-specified behavior). If the Object() constructor is changed to return a reference to a privileged object with useful properties it is possible to have attacker-supplied script executed with elevated privileges by calling the function. This could be used to install malware or take other malicious actions.
For more information and a complete list of affected products, refer to Mozilla Foundation Security Advisory 2006-51.


A remote, unauthenticated attacker may be able to execute arbitrary code on a vulnerable system. The attacker could also cause the vulnerable application to crash.


Apply an update

This vulnerability is addressed in Firefox, Thunderbird, and SeaMonkey 1.0.3, according to the Mozilla Foundation Security Update 2006-51.

Disable JavaScript

This vulnerability can be mitigated by disabling JavaScript.

Vendor Information


Mozilla, Inc. Affected

Updated:  July 27, 2006



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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This vulnerability was reported in Mozilla Foundation Security Advisory 2006-48. Mozilla credits moz_bug_r_a4 with reporting this vulnerability.

This document was written by Jeff Gennari.

Other Information

CVE IDs: CVE-2006-3807
Severity Metric: 16.03
Date Public: 2006-07-25
Date First Published: 2006-07-27
Date Last Updated: 2007-02-09 14:03 UTC
Document Revision: 12

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