Public Vulnerability Reports

Microsoft Internet Explorer Time Element Behavior Use-After-Free Vulnerability

12.13.11

BACKGROUND

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:

http://www.microsoft.com/ie/

DESCRIPTION

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

The vulnerability occurs when an HTML element within a sequence time container is replaced by another element. When the first element has already been freed, IE still keeps a reference to it in the second element. When the reference is later used to free the object, this now-invalid memory is treated as a valid object. The corrupt object's vtable is used to make an indirect function call. This may result in the execution of arbitrary code.

ANALYSIS

Exploitation of this vulnerability results in the execution of arbitrary code with the privileges of the user viewing the Web page. To exploit this vulnerability, a targeted user must load a malicious Web page that an attacker created. An attacker typically accomplishes this via social engineering or injecting content into compromised, trusted sites. After the user visits the malicious Web page, no further user interaction is needed.

DETECTION

The following Microsoft products are vulnerable:

  • Windows XP SP 3
  • Windows XP Professional x64 Edition SP 2
  • Windows Server 2003 SP 2
  • Windows Server 2003 x64 Edition SP 2
  • Windows Server 2003 with SP2 for Itanium-based Systems
  • Windows Vista SP 2
  • Windows Vista x64 Edition SP 2
  • Windows Server 2008 for 32-bit Systems SP 2
  • Windows Server 2008 for x64-based Systems SP 2
  • Windows Server 2008 for Itanium-based Systems SP 2
  • Windows 7 for 32-bit Systems and Windows 7 for 32-bit Systems SP 1
  • Windows 7 for x64-based Systems and Windows 7 for x64-based Systems SP 1
  • Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems SP 1
  • Windows Server 2008 R2 for Itanium-based Systems and Windows Server 2008 R2 for Itanium-based Systems SP 1

WORKAROUND

Microsoft suggests disabling time behavior in Windows XP and Windows Server 2003.

VENDOR RESPONSE

Microsoft has released updates to address this vulnerability. For more information, consult their advisory at the following URL.

http://technet.microsoft.com/en-us/security/bulletin/ms11-090

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2011-3397 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems.

DISCLOSURE TIMELINE

09/14/2011 Initial Vendor Notification
09/14/2011 Initial Vendor Reply
12/13/2011 Coordinated Public Disclosure

CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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LEGAL NOTICES

Copyright © 2011 Verisign, Inc.

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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.