Vulnerability Note VU#187196

Microsoft Windows fails to properly process showHelp URLs

Original Release date: 14 Jul 2004 | Last revised: 14 Jul 2004


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.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Microsoft CorporationAffected-14 Jul 2004
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



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: CAN-2003-1041
  • Date Public: 13 Jul 2004
  • Date First Published: 14 Jul 2004
  • Date Last Updated: 14 Jul 2004
  • Severity Metric: 25.51
  • Document Revision: 5


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