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Microsoft Office mailto URI remote code execution

Vulnerability Note VU#393305

Original Release Date: 2008-03-11 | Last Revised: 2008-04-01


A vulnerability in the way that Microsoft Outlook handles a certain type of hyperlink could allow a remote attacker to execute arbitrary code on the vulnerable system.


Microsoft Outlook provides a centralized application for managing and organizing e-mail messages, schedules, tasks, notes, contacts, and other information. Outlook is included as a component of newer versions of Microsoft Office and available as a stand-alone product.

Outlook exposes a vulnerability due to inadequate checking of parameters passed to the Outlook email client. The vulnerability is caused due to the manner in which Outlook interprest a mailto: URI. By creating a specially formatted mailto: URI, an attacker may be able to alter the way that Outlook is invoked in order to allow code execution. The malicious code could be delivered to the victim via a specially-crafted HTML email message or from a webpage controlled by the attacker.


Successful exploitation of this vulnerability could allow a remote, unauthenticated attacker to execute arbitrary code. Upon successful exploitation, the malicious code would be executed in the context of the "Local Machine" under the user running Outlook.


Apply Update
Microsoft has addressed this vulnerability in Microsoft Security Bulletin MS08-015.


As stated directly from MS08-015:

Disabling the mailto handler in the system registry key helps protect affected systems from attempts to exploit this vulnerability.

Vendor Information


Microsoft Corporation Affected

Updated:  March 11, 2008



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 addressed this vulnerability in Microsoft Security Bulletin MS08-015.

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

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Microsoft acknowledges Greg MacManus of iDefense Labs for reporting this vulnerability.

This document was written by Joseph W. Pruszynski.

Other Information

CVE IDs: CVE-2008-0110
Severity Metric: 26.33
Date Public: 2008-03-11
Date First Published: 2008-03-11
Date Last Updated: 2008-04-01 19:34 UTC
Document Revision: 27

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