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CERT Coordination Center

Microsoft Windows MHTML script injection vulnerability

Vulnerability Note VU#326549

Original Release Date: 2011-01-28 | Last Revised: 2011-04-12


Microsoft Windows contains an script injection vulnerability in the MHTML protocol handler, which may allow an attacker to execute arbitrary script within the context of another website domain.


Microsoft Windows contains a script injection vulnerability caused by the way MHTML interprets MIME-formatted requests for content blocks within a document. According to Microsoft TechNet Security Research & Defense blog: "It is possible under certain conditions for this vulnerability to allow an attacker to inject a client-side script in the response of a Web request run in the context of the victim's Internet Explorer. The script could spoof content, disclose information, or take any action that the user could take on the affected Web site on behalf of the targeted user."


By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message), an attacker may be able to obtain access to web content in another domain. The impact is similar to that of a cross-site scripting vulnerability. For a more detailed description of the impact of cross-site scripting vulnerabilities, please see CERT Advisory CA-2000-02.


Apply an update

This issue is addressed in Microsoft Security Bulletin MS11-026.

Lock down the MHTML protocol handler

Microsoft TechNet Security Research & Defense blog has released Microsoft Fix it 50602 to help mitigate this vulnerability.

Vendor Information


Microsoft Corporation Affected

Updated:  April 12, 2011



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Vendor References

CVSS Metrics

Group Score Vector



Thanks to Microsoft Security Response Center for reporting this vulnerability.

This document was written by Michael Orlando.

Other Information

CVE IDs: CVE-2011-0096
Severity Metric: 11.75
Date Public: 2011-01-28
Date First Published: 2011-01-28
Date Last Updated: 2011-04-12 17:31 UTC
Document Revision: 18

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