CVE-2006-4340: Mozilla Firefox

Medium severity, CVSS 4.0. EPSS: 2.3% chance of exploitation in the next 30 days.

Mozilla Network Security Service (NSS) library before 3.11.3, as used in Mozilla Firefox before 1.5.0.7, Thunderbird before 1.5.0.7, and SeaMonkey before 1.0.5, when using an RSA key with exponent 3, does not properly handle extra data in a signature, which allows remote attackers to forge signatures for SSL/TLS and email certificates, a similar vulnerability to CVE-2006-4339. NOTE: on 20061107, Mozilla released an advisory stating that these versions were not completely patched by MFSA2006-60. The newer fixes for 1.5.0.7 are covered by CVE-2006-5462.

Affected products

• Mozilla Firefox: up to and including 1.5.0.6
• Mozilla Network Security Services: up to and including 3.11.2
• Mozilla Seamonkey: up to and including 1.0.4
• Mozilla Thunderbird: up to and including 1.5.0.6

Published 2006-09-15. Last modified 2026-06-16.