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CERT Coordination Center

Learn2 STRunner ActiveX control stack buffer overflows

Vulnerability Note VU#524857

Original Release Date: 2008-02-29 | Last Revised: 2008-02-29


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.


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.


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.


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:

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_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX 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. 

Vendor Information


Learn2 Corporation Affected

Notified:  February 26, 2007 Updated: February 28, 2008



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


Please disable the vulnerable ActiveX control.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

Group Score Vector



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

This document was written by Will Dormann.

Other Information

CVE IDs: CVE-2007-6252
Severity Metric: 3.79
Date Public: 2008-02-29
Date First Published: 2008-02-29
Date Last Updated: 2008-02-29 21:02 UTC
Document Revision: 8

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