I. BACKGROUND
The HxTocCtrl ActiveX Control is a library used by the Microsoft Help
engine. More information is available at the following website.
http://en.wikipedia.org/wiki/Microsoft_Help_2
II. DESCRIPTION
Remote exploitation of a heap corruption vulnerability in Microsoft
Corp.'s Microsoft Help 2.5 ActiveX control allows an attacker to
execute arbitrary code with the privileges of the logged-on user.
Microsoft Help 2.5 installs the following ActiveX control, which is
marked as safe for scripting:
ProgID: HxVz.HxTocCtrl.1
CLSID: 314111B8-A502-11D2-BBCA-00C04F8EC294
File: %PROGRAM DIR%\Common Files\Microsoft Shared\Help\hxvz.dll
By providing malformed arguments to this control, it is possible to
corrupt heap memory.
III. ANALYSIS
Exploitation allows attackers to execute arbitrary code with the
privileges of the logged-on user. Exploitation would require an
attacker to host a maliciously crafted page on a website and entice
users to visit that site. No further action is needed other than
following a link to a malicious website. Exploitation requires that
users have the specified control installed.
IV. DETECTION
iDefense has confirmed this vulnerability in version 2.05.50727.42 of
hxvz.dll, which is installed with Visual Studio 2005.
The following products might also include vulnerable versions of the
control:
Visual Studio 2005
Visual Studio .NET 2003
Visual Studio .NET 2002
MSDN
Library 2002 - Current
BizTalk Server 2004 Standard Edition
V. WORKAROUND
Setting the kill bit for this control mitigates the threat from
web-based attacks that might be conducted via Internet Explorer. The
vulnerable CLSID is:
{314111b8-a502-11d2-bbca-00c04f8ec294}
VI. VENDOR RESPONSE
Microsoft has officially addressed this vulnerability with Security
Bulletin MS08-023. For more information, consult their bulletin at the
following URL.
http://www.microsoft.com/technet/security/bulletin/ms08-023.mspx
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2008-1086 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which
standardizes names for
security problems.
VIII. DISCLOSURE TIMELINE
12/12/2006 Initial vendor notification
12/12/2006 Initial vendor response
04/08/2008 Coordinated public disclosure
IX. CREDIT
The discoverer of this vulnerability wishes to remain anonymous.
Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php
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X. LEGAL NOTICES
Copyright © 2008 iDefense, 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. 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.
