Using Symfony2's AccessDeniedHandlerInterface

This sounds about right.

Or, if you're specifically interested in AccessDeniedException you could also define access_denied_handler within your firewall in security.yml:

security:    firewalls:        my_firewall:            # ...            access_denied_handler: kernel.listener.access_denied.handler            # ...

Then define your service in your services.xml or equivalent:

<parameters>    <parameter key="kernel.listener.security.class">Path\To\Your\Class</parameter></parameters><service id="kernel.listener.access_denied.handler" class="%kernel.listener.security.class%">    <tag name="kernel.event_listener" event="security.kernel_response" method="handle" /></service>

The handler class:

use \Symfony\Component\Security\Http\Authorization\AccessDeniedHandlerInterface;class MyAccessDeniedHandler implements AccessDeniedHandlerInterface{    public function handle(Request $request, AccessDeniedException $accessDeniedException)    {        // do something with your exception and return Response object (plain message of rendered template)    }}

You can find complete Security reference of Symfony2 here: http://symfony.com/doc/2.8/reference/configuration/security.html