Vulnerability Note VU#842094

Mozilla JavaScript cloned parent vulnerability

Original Release date: 17 Apr 2006 | Last revised: 17 May 2006


Mozilla products fail to properly restrict access to a JavaScript functions cloned parent. This vulnerability may allow a remote attacker to execute arbitrary code on a vulnerable system.


According to Mozilla Foundation Security Advisory 2006-15:

    it was possible to use the method to access an internal function object (the "clone parent") which could then be used to run arbitrary JavaScript code with full permission.
    In pre-release versions of Firefox 1.5 the same technique could be applied to the Array generic methods introduced in that release.

Note that JavaScript must be enabled in order for this vulnerability to exist. JavaScript is enabled by default in the Firefox and Mozilla web browsers, but not in the Mozilla's mail client or Thunderbird. Exploitation can occur by accessing a specially crafted web page with Firefox. If JavaScript is enabled within Mozilla's mail client or Thunderbird, then this issue may be exploitable by opening a specially crafted email.


A remote, unauthenticated attacker may be able to execute arbitrary code on a vulnerable system.


Refer to Mozilla Foundation Security Advisory 2006-15 for fixed versions of Mozilla products.

Disable JavaScript

For instructions on how to disable JavaScript in Firefox, please refer to the Firefox section of the Securing Your Web Browser document.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Mozilla, Inc.Affected-17 Apr 2006
Red Hat, Inc.Affected-17 May 2006
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This vulnerability was reported in Mozilla Foundation Security Advisory 2006-15. Mozilla credits shutdown with providing information regarding this issue.

This document was written by Jeff Gennari.

Other Information

  • CVE IDs: CVE-2006-1734
  • Date Public: 13 Apr 2006
  • Date First Published: 17 Apr 2006
  • Date Last Updated: 17 May 2006
  • Severity Metric: 20.45
  • Document Revision: 19


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