Vulnerability Note VU#725596

Microsoft WMI Administrative Tools WBEMSingleView.ocx ActiveX control vulnerability

Overview

The ActiveX control, WBEMSingleView.ocx, that is a part of the WMI Administrative Tools package contains a vulnerability.

I. Description

The AddContextRef() and ReleaseContext() functions of the WMI Object Viewer control can be passed an object pointer from an attacker that results in arbitrary code execution. An Internet Explorer user with WBEMSingleView.ocx installed can be exploited by visiting a malicious web page.

II. Impact

An attacker can execute arbitrary code as the user.

III. Solution

We are currently unaware of a practical solution to this problem.

Disable the WMI Object Viewer ActiveX control in Internet Explorer

The vulnerable ActiveX control can be disabled in Internet Explorer by setting the kill bit for the following CLSID:

{2745E5F5-D234-11D0-847A-00C04FD7BB08}

More information about how to set the kill bit is available in Microsoft Support Document 240797. Alternatively, the following text can be saved as a .REG file and imported to set the kill bit for this control:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESOFTWAREMicrosoftInternet ExplorerActiveX Compatibility{2745E5F5-D234-11D0-847A-00C04FD7BB08}]
"Compatibility Flags"=dword:00000400
[HKEY_LOCAL_MACHINESOFTWAREWow6432NodeMicrosoftInternet ExplorerActiveX Compatibility{2745E5F5-D234-11D0-847A-00C04FD7BB08}]
"Compatibility Flags"=dword:00000400

Disable ActiveX

Disabling ActiveX controls in the Internet Zone (or any zone used by an attacker) appears to prevent exploitation of this and other ActiveX vulnerabilities. Instructions for disabling ActiveX in the Internet Zone can be found in the "Securing Your Web Browser" document.

Vendor Information

Vendor	Status	Date Notified	Date Updated
Microsoft Corporation	Affected		2010-12-22

References

http://www.cert.org/tech_tips/securing_browser/
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=6430f853-1120-48db-8cc5-f2abdc3ed314
http://support.microsoft.com/kb/240797
http://www.wooyun.org/bugs/wooyun-2010-01006
http://secunia.com/advisories/42693

Credit

This vulnerability was publicly disclosed on WooYun.org.

This document was written by Jared Allar.

Other Information

Date Public:	2010-12-22
Date First Published:	2010-12-22
Date Last Updated:	2010-12-22
CERT Advisory:
CVE-ID(s):
NVD-ID(s):
US-CERT Technical Alerts:
Severity Metric:	3.94
Document Revision:	13