CVE-2013-6673: Canonical Ubuntu Linux

Medium severity, CVSS 5.9. EPSS: 2.9% chance of exploitation in the next 30 days.

Mozilla Firefox before 26.0, Firefox ESR 24.x before 24.2, Thunderbird before 24.2, and SeaMonkey before 2.23 do not recognize a user's removal of trust from an EV X.509 certificate, which makes it easier for man-in-the-middle attackers to spoof SSL servers in opportunistic circumstances via a valid certificate that is unacceptable to the user.

Affected products

• Canonical Ubuntu Linux: version 12.04 only; version 12.10 only; version 13.04 only; version 13.10 only
• Fedoraproject Fedora: version 18 only; version 19 only; version 20 only
• Mozilla Firefox: before 26.0 (fixed in 26.0); from 24.0, before 24.2 (fixed in 24.2)
• Mozilla Seamonkey: before 2.23 (fixed in 2.23)
• Mozilla Thunderbird: before 24.2 (fixed in 24.2)
• Opensuse Opensuse: version 12.2 only; version 12.3 only; version 13.1 only
• Suse Linux Enterprise Desktop: version 11 only
• Suse Linux Enterprise Server: version 11 only
• Suse Suse Linux Enterprise Software Development Kit: version 11.0 only

Published 2013-12-11. Last modified 2026-06-17.