Vulnerability Note VU#813230

Mozilla products vulnerable to privilege escalation via XBL.method.eval

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


A vulnerability in the way Mozilla products and derivative programs handle certain XBL methods could allow a remote attacker to execute arbitrary code on a vulnerable system.


The Mozilla browser and derived products include support for the Extensible Bindings Language (XBL), a markup language that defines special new elements, or "bindings" for Mozilla's XML-based User interface Language (XUL) widgets and HTML elements. A vulnerability has been discovered in the way that Mozilla and derived products handle some methods of XBL bindings. Mozilla Foundation Security Advisory 2006-14 states the following:

    Using the eval associated with methods of an XBL binding it was possible to create JavaScript functions that would get compiled with the wrong privileges, allowing the attacker to run code of their choice with the full permission of the user running the browser. This could be used to install spyware or viruses.

    Note: Thunderbird shares the JavaScript engine with Firefox and could be vulnerable if JavaScript were to be enabled in mail. This is not the default setting and we strongly discourage users from running JavaScript in mail.


A remote attacker may be able to run code of their choosing on an affected system. The attacker-supplied code would be executed with the permissions of the user running the vulnerable program.



The Mozilla Foundation has published Mozilla Foundation Security Advisory 2006-14 in response to this issue. Users are encouraged to review this advisory and upgrade to the fixed versions of the products it describes.


Users, particularly those who are unable to upgrade to a fixed version of the software, are encouraged to disable JavaScript in the affected program.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Mozilla, Inc.Affected17 Apr 200617 Apr 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



Thanks to Mozilla Foundation Security Advisory for reporting this vulnerability.

This document was written by Chad Dougherty based on information supplied by the Mozilla Foundation.

Other Information

  • CVE IDs: CVE-2006-1735
  • Date Public: 13 Apr 2006
  • Date First Published: 17 Apr 2006
  • Date Last Updated: 17 Apr 2006
  • Severity Metric: 24.30
  • Document Revision: 6


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