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CERT Coordination Center

Mozilla fails to properly handle script-generated events

Vulnerability Note VU#460528

Original Release Date: 2004-09-17 | Last Revised: 2004-09-17


There is a vulnerability the way Mozilla handles script-generated events that could allow a remote, unauthenticated attacker to access data contained on the victim's clipboard.


Mozilla is an open-source web browser, email/newsgroup client, IRC client, and HTML editor available for a number of platforms including Microsoft Windows, Linux, and other UNIX platforms. When a web page is loaded by the browser, it will accept certain JavaScript events to control behavior on the page. These script-generated events can be applied to text fields.

There is a vulnerability in the way Mozilla handles copy/paste keyboard shortcut sequences sent to text fields using JavaScript. While Mozilla restricts the use of copy (Ctrl+C) and paste (Ctrl+V) keyboard shortcut sequences, it fails to restrict other variations such as Ctrl+Ins (copy) and Shift+Ins (paste). Exploitation of this vulnerability could allow a remote, unauthenticated attacker to access the victim's clipboard.


By convincing a victim to view a malicious web page, a remote, unauthenticated attacker could perform read/write operations to the victim's clipboard. Since users may copy/paste usernames, passwords, or potentially other sensitive information to the clipboard, the attacker could gain access to this information.


Upgrade as specified by your vendor. This issue has been resolved in Mozilla 1.7.3, Firefox Preview Release, and Thunderbird 0.8.

Disable JavaScript

Disable JavaScript in your browser's preferences.

Vendor Information


Mozilla Affected

Updated:  September 17, 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.


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 by Wladimir Palant.

This document was written by Damon Morda.

Other Information

CVE IDs: None
Severity Metric: 16.88
Date Public: 2004-08-31
Date First Published: 2004-09-17
Date Last Updated: 2004-09-17 20:14 UTC
Document Revision: 19

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