Symfony permission denied
You can take a look at http://symfony.com/doc/current/book/installation.html on "Setting up Permissions" section. It talks about app/logs and app/cache, but you can do the same on any other folder you need
In Symfony3, I had this error after installing symfony in a new fresh VPS, I resolved it using the already noted : chmod -R 775 for the LOG and CACHE but now for the SESSIONS folder.
chmod -R 775 var/sessions
Similar symfony permissions issue this worked for me:
sudo chown <yourcliusername> /var/lib/php5