This website uses cookies to distinguish you from other users of our website. The use of cookies helps us to provide you with a specific service, to facilitate website use, to understand our visitors and to advertise to you. By continuing to browse the site you are giving consent to our use of cookies. Learn more in our Privacy Statement.

Security Services

Microsoft Internet Explorer 8 mshtml!CTreeNode List Element Use-after-Free Vulnerability



Internet Explorer (IE) is a graphical Web browser developed by Microsoft Corp. that has been included with Microsoft Windows since 1995. For more information about Internet Explorer, please the visit following website:


Remote exploitation of a use-after-free vulnerability in multiple versions of Microsoft Corp.'s Internet Explorer could allow an attacker to execute arbitrary code with the privileges of the current user.

A use-after-free vulnerability exists in the way Internet Explorer handles stylized CSS on list elements within HTML documents. Specifically, the issue occurs within how the mshtml!CTreeNode object handles list-stylized elements.


Exploitation of this issue allows an attacker to execute arbitrary code with the privileges of the current user. An attacker would need to entice a victim to visit a specially crafted Web page. Upon visiting the page, exploitation would occur and execution of arbitrary code would be possible.


Internet Explorer 8 and 9 are vulnerable.


iDefense Provided:

  • Utilize EMET
Vendor Provided:

  • Set Internet and Local intranet security zone settings to "High" to block ActiveX Controls and Active Scripting in these zones
  • Configure Internet Explorer to prompt before running Active Scripting or to disable Active Scripting in the Internet and local intranet security zone


Microsoft has released a fix which addresses this issue. For more information, consult their advisory at the following URL:


The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2013-0811 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


02/21/2013 Initial Vendor Notification
02/21/2013 Initial Vendor Reply
05/14/2013 Coordinated Public Disclosure


This vulnerability was reported to iDefense by Jose A. Vazquez of Yenteasy - Security Research.

Get paid for vulnerability research

Free tools, research and upcoming events


Copyright © 2013 Verisign, Inc.

Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDefense Verisign. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please e-mail customer service for permission.

Disclaimer: The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.