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Corel / Micrografx ActiveCGM Browser ActiveX control buffer overflows

Vulnerability Note VU#983249

Original Release Date: 2007-06-13 | Last Revised: 2007-06-13


The Corel / Micrografx ActiveCGM Browser ActiveX control contains multiple buffer overflows, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.


The Corel ActiveCGM Browser is an ActiveX control that allows viewing of Computer Graphic Metafiles (CGMs) in a web browser. The ActiveCGM Browser ActiveX control, which is provided by acgm.dll, contains multiple buffer overflows. Note that the control was created by Micrografx, which was acquired by Corel.


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 Internet Explorer (or the program using the WebBrowser control) to crash.


Apply an update

This vulnerability is addressed in version of the ActiveCGM Browser ActiveX control. Please check with your vendor for update availability. Also consider the following workarounds

Disable the ActiveCGM 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\{F5D98C43-DB16-11cf-8ECA-0000C0FD59C7}]
"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


Corel Corporation Affected

Notified:  August 17, 2006 Updated: June 11, 2007



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.


This vulnerability is addressed in version of the ActiveCGM Browser ActiveX control. Please check with your vendor for update availability.

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 CERT/CC.

This document was written by Will Dormann.

Other Information

CVE IDs: CVE-2007-2921
Severity Metric: 1.95
Date Public: 2007-06-13
Date First Published: 2007-06-13
Date Last Updated: 2007-06-13 17:50 UTC
Document Revision: 7

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