CVE-2005-0399: Mozilla Firefox

Medium severity, CVSS 5.1. EPSS: 15.1% chance of exploitation in the next 30 days.

Heap-based buffer overflow in GIF2.cpp in Firefox before 1.0.2, Mozilla before to 1.7.6, and Thunderbird before 1.0.2, and possibly other applications that use the same library, allows remote attackers to execute arbitrary code via a GIF image with a crafted Netscape extension 2 block and buffer size.

Affected products

• Mozilla Firefox: version 0.8 only; version 0.9 only; version 0.9.1 only; version 0.9.2 only; version 0.9.3 only; version 0.10 only; …
• Mozilla Mozilla: version 1.3 only; version 1.4 only; version 1.4.1 only; version 1.5 only; version 1.5.1 only; version 1.6 only; …
• Mozilla Thunderbird: version 0.1 only; version 0.2 only; version 0.3 only; version 0.4 only; version 0.5 only; version 0.6 only; …

Published 2005-05-02. Last modified 2026-06-16.