CVE-2009-2408: Canonical Ubuntu Linux

Medium severity, CVSS 5.9. EPSS: 5% chance of exploitation in the next 30 days.

Mozilla Network Security Services (NSS) before 3.12.3, Firefox before 3.0.13, Thunderbird before 2.0.0.23, and SeaMonkey before 1.1.18 do not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority. NOTE: this was originally reported for Firefox before 3.5.

Affected products

• Canonical Ubuntu Linux: version 8.04 only; version 8.10 only; version 9.04 only
• Debian Debian Linux: version 5.0 only
• Mozilla Firefox: before 3.0.13 (fixed in 3.0.13)
• Mozilla Network Security Services: before 3.12.3 (fixed in 3.12.3)
• Mozilla Seamonkey: before 1.1.18 (fixed in 1.1.18)
• Mozilla Thunderbird: before 2.0.0.23 (fixed in 2.0.0.23)
• Opensuse Opensuse: from 10.3, up to and including 11.1
• Suse Linux Enterprise: version 10.0 only; version 11.0 only
• Suse Linux Enterprise Server: version 9 only

Published 2009-07-30. Last modified 2026-06-16.