Vulnerability Note VU#735441

Gateway CWebLaunchCtl ActiveX control buffer overflow

Overview

The Gateway CWebLaunchCtl ActiveX control contains a buffer overflow, which may allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable sytem.

I. Description

The Gateway Computers CWebLaunchCtlActiveX control, which is provided by weblaunch.ocx, contains a buffer overflow in the DoWebLaunch() method.

II. Impact

By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message or attachment), an attacker may be able to execute arbitrary code with the privileges of the user. The attacker could also cause the web browser to crash.

III. Solution

We are currently unaware of a practical solution to this problem. Please consider the following workarounds

Disable the CWebLaunchCtl ActiveX control in Internet Explorer

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

{93CEA8A4-6059-4E0B-ADDD-73848153DD5E}

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{93CEA8A4-6059-4E0B-ADDD-73848153DD5E}]
"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.

Systems Affected

Vendor	Status	Date Updated
Gateway	Vulnerable	8-Jan-2008

References

http://www.cert.org/tech_tips/securing_browser/#Internet_Explorer
http://milw0rm.com/exploits/4869
http://secunia.com/advisories/28379/

Credit

This vulnerability was reported by Will Dormann of the CERT/CC. It was also independently discovered and publicly disclosed by Elazar Broad.

This document was written by Will Dormann.

Other Information

Date Public	01/08/2008
Date First Published	01/08/2008 06:09:58 PM
Date Last Updated	01/11/2008
CERT Advisory
CVE Name
Metric	13.66
Document Revision	8