Vulnerability Note VU#393305

Microsoft Office mailto URI remote code execution

Original Release date: 11 Mar 2008 | Last revised: 01 Apr 2008


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.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Microsoft CorporationAffected-11 Mar 2008
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

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



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
  • Date Public: 11 Mar 2008
  • Date First Published: 11 Mar 2008
  • Date Last Updated: 01 Apr 2008
  • Severity Metric: 26.32
  • Document Revision: 25


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