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CERT Coordination Center

Yahoo! Messenger "addview" function allows for the automatic execution of malicious script contained in web pages

Vulnerability Note VU#172315

Original Release Date: 2002-06-05 | Last Revised: 2002-06-05


Yahoo! Messenger is an instant messaging client. When installed, Yahoo! Messenger enables a URI handler (ymsgr :parameter). The addview function of this handler can be used to execute arbitrary script/html on the local system.


The addview feature of Yahoo! Messenger is used to allow users to view content from a site that is formatted in the Yahoo! Messenger format without the need for a stand-alone web browser. If the attacker can trick the user into visiting a website or opening an HTML-renderable email, the attacker can exploit this vulnerability to execute arbitrary script/HTML on the local system with the privileges of the current user.


An attacker can send malicious script and HTML to the client using the Yahoo! URL redirection service. This script or HTML is interpreted by the Yahoo! Messenger client and is displayed in the client's web browser. The arbitrary script/HTML is executed on the local system in the Internet security zone.


Upgrade to version 5,0,0,1066.

Vendor Information


Yahoo Affected

Notified:  May 29, 2002 Updated: June 05, 2002



Vendor Statement

Yahoo! encourages users to upgrade to the latest version whenever prompted by the AutoUpdater or regularly check for updated versions of the client at

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


The CERT/CC has no additional comments at this time.

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

CVSS Metrics

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This vulnerability was reported on by Phuong Nguyen of Vice Consulting.

This document was written by Jason Rafail.

Other Information

CVE IDs: CVE-2002-0032
CERT Advisory: CA-2002-16
Severity Metric: 23.73
Date Public: 2002-05-27
Date First Published: 2002-06-05
Date Last Updated: 2002-06-05 21:07 UTC
Document Revision: 23

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