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Microsoft Windows "MHTML" protocol handler fails to properly interpret HTTP header

Vulnerability Note VU#682825

Original Release Date: 2007-06-13 | Last Revised: 2007-06-21

Overview

Microsoft Windows "MHTML" protocol handler fails to properly interpret HTTP headers, which may cause information disclosure.

Description

The Microsoft Windows "MHTML" protocol handler contains an information disclosure vulnerability in the way that it interprets HTTP headers. The "MHTML" protocol handler fails to properly interpret HTTP headers when returning MHTML content, which may allow Internet Explorer to bypass Internet Explorer domain restrictions.

Impact

By convincing a user to visit a specially crafted website, a remote, unauthenticated attacker may be able to access sensitive information.

Solution

Apply an update

This issue is addressed by Microsoft Security Bulletin MS07-034.

Workarounds


Microsoft has provided the following workarounds to address this issue:

Disable the MHTML protocol handler.

1. Click Start and then click Run. Enter regedit.exe in the text box and click OK.
2. Navigate to HKEY_CLASSES_ROOT\CLSID\{05300401-BCBC-11d0-85E3-00C04FD85AB4}.
3. Right click {05300401-BCBC-11d0-85E3-00C04FD85AB4} and select Permissions.
4. Click Advanced.
5. Uncheck Allow inheritable permissions from the parent to propagate…
6. Click Remove, and then click OK. Click Yes and OKon subsequent screens.
Impact of workaround: This workaround disables page rendering for MHTML Web pages.


Configure Internet Explorer to prompt before running Active Scripting or to disable Active Scripting in the Internet and Local intranet security zone.

1. In Internet Explorer, click Internet Options on the Tools menu.
2. Click the Security tab.
3. Click Internet, and then click Custom Level.
4. Under Settings, in the Scripting section, under Active Scripting, click Prompt or Disable, and then click OK.
5. Click Local intranet, and then click Custom Level.
6. Under Settings, in the Scripting section, under Active Scripting, click Prompt or Disable, and then click OK.
7. Click OK two times to return to Internet Explorer.

Please see Microsoft Security Bulletin MS07-034 for further details.

Vendor Information

682825
 
Affected   Unknown   Unaffected

Microsoft Corporation

Updated:  June 13, 2007

Status

  Vulnerable

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

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

Addendum

This issue is addressed by Microsoft Security Bulletin MS07-034.

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


CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A

References

Acknowledgements

This vulnerability was reported in Microsoft Security Bulletin MS07-034 . Microsoft thanks SANS ISC for their assistance.

This document was written by Katie Steiner.

Other Information

CVE IDs: CVE-2007-2225
Date Public: 2007-06-12
Date First Published: 2007-06-13
Date Last Updated: 2007-06-21 19:35 UTC
Document Revision: 9

Sponsored by the Department of Homeland Security Office of Cybersecurity and Communications.