search menu icon-carat-right cmu-wordmark

CERT Coordination Center

Microsoft Windows fails to properly process showHelp URLs

Vulnerability Note VU#187196

Original Release Date: 2004-07-14 | Last Revised: 2004-07-14


A vulnerability in the showHelp Method may allow a remote attacker to execute arbitrary code.


A cross domain vulnerability exists in the showHelp method that may permit a remote attacker to execute local commands on the system with the privileges of the current user. Explotation of this vulnerability would require the user to visit a malicious website or otherwise visit a crafted URL and then take several interactive steps.

Note that Microsoft states that they have received reports that this vulnerability is being actively exploited.

For full details, please see the "showHelp Vulnerability - CAN-2003-1041" section of Microsoft Security Bulletin MS04-023.


A remote attacker may be able to execute local commands on the system with the privileges of the current user.


Microsoft has provided a patch in Microsoft Security Bulletin MS04-023.

Microsoft recommends several workarounds to help mitigate attack vectors. These include Strengthen the security settings for the Local Machine zone in Internet Explorer, unregistering HTML Help, and reading e-mail messages in plain-text format. Please see Microsoft Security Bulletin MS04-023 for full details and impacts of implementing these workarounds.

Vendor Information


Microsoft Corporation Affected

Updated:  July 14, 2004



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.


Please see Microsoft Security Bulletin MS04-023.

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

CVSS Metrics

Group Score Vector



Thanks to Microsoft for reporting this vulnerability.

This document was written by Jason A Rafail and is based on information from Microsoft Security Bulletin MS04-023.

Other Information

CVE IDs: CVE-2003-1041
Severity Metric: 25.52
Date Public: 2004-07-13
Date First Published: 2004-07-14
Date Last Updated: 2004-07-14 15:36 UTC
Document Revision: 6

Sponsored by CISA.