CVE-2013-6167: Mozilla Firefox

Medium severity, CVSS 6.8. EPSS: 1.6% chance of exploitation in the next 30 days.

Mozilla Firefox through 27 sends HTTP Cookie headers without first validating that they have the required character-set restrictions, which allows remote attackers to conduct the equivalent of a persistent Logout CSRF attack via a crafted parameter that forces a web application to set a malformed cookie within an HTTP response.

Affected products

• Mozilla Firefox: up to and including 27.0

Published 2014-02-15. Last modified 2026-06-17.