CVE-2009-2463: Mozilla Firefox

High severity, CVSS 10.0. EPSS: 6.4% chance of exploitation in the next 30 days.

Multiple integer overflows in the (1) PL_Base64Decode and (2) PL_Base64Encode functions in nsprpub/lib/libc/src/base64.c in Mozilla Firefox before 3.0.12, Thunderbird before 2.0.0.24, and SeaMonkey before 1.1.19 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unspecified vectors that trigger buffer overflows.

Affected products

• Mozilla Firefox: version 0.1 only; version 0.2 only; version 0.3 only; version 0.4 only; version 0.5 only; version 0.6 only; …
• Mozilla Thunderbird: version 2.0.0.0 only; version 2.0.0.1 only; version 2.0.0.2 only; version 2.0.0.3 only; version 2.0.0.4 only; version 2.0.0.5 only; …

Published 2009-07-22. Last modified 2026-06-16.