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CERT Coordination Center

Mozilla products vulnerable to heap overflow via specially crafted GIF file

Vulnerability Note VU#557948

Original Release Date: 2005-03-30 | Last Revised: 2005-12-22


Mozilla products, including the Mozilla Suite, Mozilla Firefox, and Mozilla Thunderbird, are vulnerable to a heap-based overflow in the GIF image-processing routines.


The Mozilla project produces an application suite (Mozilla Suite), web browsers (Mozilla Firefox), email software (Mozilla Thunderbird), and other products.

An image processing library used in some Mozilla products contains a flaw in Graphic Interchange Format (GIF) file handling. A Netscape-specific extension block (Netscape extension 2) may be present in the GIF file that contains a 32-bit integer. This integer is used to determine image buffer space. An attacker may misrepresent this value to exploit a heap overflow condition. The attacker can craft a special GIF file that, when viewed, induces a heap overflow in the Mozilla product that is processing the GIF file.


A remote unauthenticated attacker can execute arbitrary code as the local user if the user loads a specially crafted GIF file (for example, a GIF-format image in a web page or email message).


Apply an update

The vulnerability is addressed in the following Mozilla product releases:

Mozilla Suite 1.7.6
Mozilla Firefox 1.0.2
Mozilla Thunderbird 1.0.2

Note that other products that use the same image processing library may also be affected.

The Mozilla project recommends turning off image loading as a temporary workaround until an update is applied.

Vendor Information


Mozilla Affected

Notified:  March 22, 2005 Updated: March 28, 2005



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 Mozilla Organzation has provided information on this vulnerability in Mozilla Foundation Security Advisory 2005-30.

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

Red Hat, Inc. Affected

Updated:  December 22, 2005



Vendor Statement

Updated Mozilla packages (for Red Hat Enterprise Linux 4, 3, and 2.1) and
updated Firefox and Thunderbird packages (for Red Hat Enterprise Linux 4)
to correct this issue are available at the URL below and by using the Red
Hat Network 'up2date' tool.

Vendor Information

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

CVSS Metrics

Group Score Vector



Thanks to Mark Dowd and the rest of ISS X-Force for reporting this vulnerability.

This document was written by Ken MacInnis.

Other Information

CVE IDs: CVE-2005-0399
Severity Metric: 17.55
Date Public: 2005-03-23
Date First Published: 2005-03-30
Date Last Updated: 2005-12-22 20:14 UTC
Document Revision: 35

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