Vulnerability Note VU#326549

Microsoft Windows MHTML script injection vulnerability

Overview

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.

I. Description

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."

II. Impact

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.

III. Solution

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

Vendor	Status	Date Notified	Date Updated
Microsoft Corporation	Affected		2011-04-12

References

http://www.microsoft.com/technet/security/bulletin/ms11-026.mspx
http://www.microsoft.com/technet/security/advisory/2501696.mspx
http://blogs.technet.com/srd/
http://go.microsoft.com/?linkid=9760419

Credit

Thanks to Microsoft Security Response Center for reporting this vulnerability.

This document was written by Michael Orlando.

Other Information

Date Public:	2011-01-28
Date First Published:	2011-01-28
Date Last Updated:	2011-04-12
CERT Advisory:
CVE-ID(s):	CVE-2011-0096
NVD-ID(s):	CVE-2011-0096
US-CERT Technical Alerts:
Severity Metric:	11.75
Document Revision:	17