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Microsoft Cryptographic API Component Object Model Certificates ActiveX control contains a remote code execution vulnerability

Vulnerability Note VU#866305

Original Release Date: 2007-05-08 | Last Revised: 2007-08-14


Microsoft Cryptographic API Component Object Model (CAPICOM) Certificates ActiveX control contains a vulnerability that may allow a remote, unauthenticated attacker to execute arbitrary code.


The Microsoft Cryptographic API Component Object Model (CAPICOM) Certificates ActiveX control provides a method of encrypting data using Windows CryptoAPI functionality. A vulnerability exists in the way that the CAPICOM.Certificates control validates input. By convincing a user to visit a malicious web site, an attacker may be able to execute arbitrary code.


A remote, unauthenticated attacker may be able to gain control of the system, execute arbitrary code, or access the system with escalated privileges.


Apply an Update

Microsoft has released updates in Microsoft Security Bulletin MS07-028 to address this issue.

This control also has been disabled via the kill bit in Microsoft Security Bulletin MS07-045.


Disable the CAPICOM.Certificate ActiveX control in Internet Explorer.

The CAPICOM Certificate ActiveX control can be disabled in Internet Explorer by setting the kill bit for the following CLSIDs:


More information about how to set the kill bit is available in Microsoft Support Document 240797.

Microsoft has releases several additional workarounds to mitigate this issue. Please see Microsoft Security Bulletin MS07-028 for further details.

Vendor Information


Microsoft Corporation Affected

Updated:  May 08, 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.


Microsoft has published Microsoft Security Bulletin MS07-028 in response to this issue. Users are encouraged to review this bulletin and apply the referenced patches.

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

CVSS Metrics

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This vulnerability was reported in Microsoft Security Bulletin MS07-028. Microsoft credits Chris Ries of VigilantMinds Inc. for reporting the vulnerability to them.

This document was written by Katie Steiner.

Other Information

CVE IDs: CVE-2007-0940
Severity Metric: 3.09
Date Public: 2007-05-08
Date First Published: 2007-05-08
Date Last Updated: 2007-08-14 18:00 UTC
Document Revision: 18

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