Symfony 2.3.x before 2.3.35, 2.6.x before 2.6.12, and 2.7.x before 2.7.7 might allow remote attackers to have unspecified impact via a timing attack involving the (1) Symfony/Component/Security/Http/RememberMe/PersistentTokenBasedRememberMeServices or (2) Symfony/Component/Security/Http/Firewall/DigestAuthenticationListener class in the Symfony Security Component, or (3) legacy CSRF implementation from the Symfony/Component/Form/Extension/Csrf/CsrfProvider/DefaultCsrfProvider class in the Symfony Form component.
lists.fedoraproject.org/pipermail/package-announce/2015-December/173271.html
lists.fedoraproject.org/pipermail/package-announce/2015-December/173300.html
www.debian.org/security/2015/dsa-3402
www.securityfocus.com/bid/77692
symfony.com/blog/cve-2015-8125-potential-remote-timing-attack-vulnerability-in-security-remember-me-service