When working with Symfony2, you already have many of the finest tools for securing your web application. There are cases however that require you to add that extra bit. In this post I will point you to the right extension points within a Symfony2 project (or any other project which uses the Security Component for that matter).

Install NelmioSecurityBundle

See the README of the NelmioSecurityBundle. It contains many add-ons for your project, to sign/encrypt cookies, force SSL, prevent clickjacking and prevent untrusted redirects.