search menu icon-carat-right cmu-wordmark

CERT Coordination Center

Microsoft Internet Explorer may handle certain web pages in an incorrect, less restrictive security zone (MS02-023)

Vulnerability Note VU#242891

Original Release Date: 2002-05-30 | Last Revised: 2002-08-26


Microsoft Internet Explorer (IE) may handle malformed Internet pages accessed through the NetBIOS protocol as if they belong to the IE's Intranet or Trusted Sites security zones, instead of the more restrictive Internet security zone.


If a user views a page on the Internet that has been malformed in a certain way to exploit the client's particular configuration, then IE may render the page using the less restrictive security settings of the Intranet zone or the Trusted Sites zone. This vulnerability cannot be exploited unless the user views the page using the NetBIOS protocol instead of HTTP.


A malicious web page may be rendered on the client host using less restrictive security settings than are appropriate for Internet pages. The specific impacts depend on the privileges specified in the client's settings for the Intranet and Trusted Sites zones.


Apply a patch from your vendor

See Microsoft Security Bulletin MS02-023 for more information:

Disable NetBIOS access to external networks.

Vendor Information


Microsoft Corporation Affected

Notified:  May 30, 2002 Updated: June 04, 2002



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.


See Microsoft Security Bulletin MS02-023 for more information:

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 Shawn Van Ittersum.

Other Information

CVE IDs: CVE-2002-0190
Severity Metric: 2.99
Date Public: 2002-05-15
Date First Published: 2002-05-30
Date Last Updated: 2002-08-26 18:03 UTC
Document Revision: 17

Sponsored by CISA.