Security

class SecurityComponent(ComponentCollection $collection, array $config = [])

The Security Component creates an easy way to integrate tighter security in your application. It provides methods for various tasks like:

  • Restricting which HTTP methods your application accepts.
  • Form tampering protection
  • Requiring that SSL be used.
  • Limiting cross controller communication.

Like all components it is configured through several configurable parameters. All of these properties can be set directly or through setter methods of the same name in your controller’s beforeFilter.

By using the Security Component you automatically get form tampering protection. Hidden token fields will automatically be inserted into forms and checked by the Security component.

If you are using Security component’s form protection features and other components that process form data in their startup() callbacks, be sure to place Security Component before those components in your initialize() method.

Note

When using the Security Component you must use the FormHelper to create your forms. In addition, you must not override any of the fields’ “name” attributes. The Security Component looks for certain indicators that are created and managed by the FormHelper (especially those created in View\Helper\FormHelper::create() and View\Helper\FormHelper::end()). Dynamically altering the fields that are submitted in a POST request (e.g. disabling, deleting or creating new fields via JavaScript) is likely to cause the request to be send to the blackhole callback.

You should always verify the HTTP method being used before executing side-effects. You should check the HTTP method or use Cake\Http\ServerRequest::allowMethod() to ensure the correct HTTP method is used.

Handling Blackhole Callbacks

SecurityComponent::blackHole(object $controller, string $error = '', SecurityException $exception = null)

If an action is restricted by the Security Component it is ‘black-holed’ as an invalid request which will result in a 400 error by default. You can configure this behavior by setting the blackHoleCallback configuration option to a callback function in the controller.

By configuring a callback method you can customize how the blackhole process works:

public function beforeFilter(Event $event)
{
    $this->Security->config('blackHoleCallback', 'blackhole');
}

public function blackhole($type)
{
    // Handle errors.
}

The $type parameter can have the following values:

  • ‘auth’ Indicates a form validation error, or a controller/action mismatch error.
  • ‘secure’ Indicates an SSL method restriction failure.

New in version cakephp/cakephp: 3.2.6

As of v3.2.6 an additional parameter is included in the blackHole callback, an instance of the Cake\Controller\Exception\SecurityException is included as a second parameter.

Restrict Actions to SSL

SecurityComponent::requireSecure()

Sets the actions that require a SSL-secured request. Takes any number of arguments. Can be called with no arguments to force all actions to require a SSL-secured.

SecurityComponent::requireAuth()

Sets the actions that require a valid Security Component generated token. Takes any number of arguments. Can be called with no arguments to force all actions to require a valid authentication.

Restricting Cross Controller Communication

allowedControllers
A list of controllers which can send requests to this controller. This can be used to control cross controller requests.
allowedActions
A list of actions which are allowed to send requests to this controller’s actions. This can be used to control cross controller requests.

These configuration options allow you to restrict cross controller communication. Set them with the config() method.

Form Tampering Prevention

By default the SecurityComponent prevents users from tampering with forms in specific ways. The SecurityComponent will prevent the following things:

  • Unknown fields cannot be added to the form.
  • Fields cannot be removed from the form.
  • Values in hidden inputs cannot be modified.

Preventing these types of tampering is accomplished by working with the FormHelper and tracking which fields are in a form. The values for hidden fields are tracked as well. All of this data is combined and turned into a hash. When a form is submitted, the SecurityComponent will use the POST data to build the same structure and compare the hash.

Note

The SecurityComponent will not prevent select options from being added/changed. Nor will it prevent radio options from being added/changed.

unlockedFields
Set to a list of form fields to exclude from POST validation. Fields can be unlocked either in the Component, or with FormHelper::unlockField(). Fields that have been unlocked are not required to be part of the POST and hidden unlocked fields do not have their values checked.
validatePost
Set to false to completely skip the validation of POST requests, essentially turning off form validation.

The above configuration options can be set with config().

Usage

Using the security component is generally done in the controllers beforeFilter(). You would specify the security restrictions you want and the Security Component will enforce them on its startup:

namespace App\Controller;

use App\Controller\AppController;
use Cake\Event\Event;

class WidgetsController extends AppController
{

    public function initialize()
    {
        parent::initialize();
        $this->loadComponent('Security');
    }

    public function beforeFilter(Event $event)
    {
        if ($this->request->getParam('admin')) {
            $this->Security->requireSecure();
        }
    }
}

The above example would force all actions that had admin routing to require secure SSL requests:

namespace App\Controller;

use App\Controller\AppController;
use Cake\Event\Event;

class WidgetsController extends AppController
{

    public function initialize()
    {
        parent::initialize();
        $this->loadComponent('Security', ['blackHoleCallback' => 'forceSSL']);
    }

    public function beforeFilter(Event $event)
    {
        if ($this->request->getParam('admin')) {
            $this->Security->requireSecure();
        }
    }

    public function forceSSL()
    {
        return $this->redirect('https://' . env('SERVER_NAME') . $this->request->here());
    }
}

This example would force all actions that had admin routing to require secure SSL requests. When the request is black holed, it will call the nominated forceSSL() callback which will redirect non-secure requests to secure requests automatically.

CSRF Protection

CSRF or Cross Site Request Forgery is a common vulnerability in web applications. It allows an attacker to capture and replay a previous request, and sometimes submit data requests using image tags or resources on other domains. To enable CSRF protection features use the Cross Site Request Forgery.

Disabling Security Component for Specific Actions

There may be cases where you want to disable all security checks for an action (ex. AJAX requests). You may “unlock” these actions by listing them in $this->Security->unlockedActions in your beforeFilter(). The unlockedActions property will not affect other features of SecurityComponent:

namespace App\Controller;

use App\Controller\AppController;
use Cake\Event\Event;

class WidgetController extends AppController
{

    public function initialize()
    {
        parent::initialize();
        $this->loadComponent('Security');
    }

    public function beforeFilter(Event $event)
    {
         $this->Security->config('unlockedActions', ['edit']);
    }
}

This example would disable all security checks for the edit action.