Vulnerability Note VU#524857

Learn2 STRunner ActiveX control stack buffer overflows

Overview

The Learn2 STRunner ActiveX control contains multiple stack buffer overflows, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.

I. Description

The Learn2 Corporation STRunner ActiveX control, which is provided by iestm32.dll, can view multimedia streams that are commonly used in online tutorials. This ActiveX control, which is also known as the Street Technologies ActiveX Control, contains multiple stack buffer overflow vulnerabilities.

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.

III. Solution

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

Disable the Learn2 STRunner ActiveX control in Internet Explorer

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

{0B72CCA4-5F11-11D0-9CB5-0000C0EC9FDB}

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{0B72CCA4-5F11-11D0-9CB5-0000C0EC9FDB}]
"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
Learn2 Corporation	Vulnerable	28-Feb-2008

References

http://www.cert.org/tech_tips/securing_browser
http://www.securityfocus.com/bid/28058
http://support.microsoft.com/kb/240797

Credit

This vulnerability was reported by Will Dormann of the CERT/CC.

This document was written by Will Dormann.

Other Information

Date Public	02/29/2008
Date First Published	02/29/2008 11:05:16 AM
Date Last Updated	02/29/2008
CERT Advisory
CVE Name	CVE-2007-6252
US-CERT Technical Alerts
Metric	3.79
Document Revision	7