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Business information leak

Need​

Protection of sensitive business information from unauthorized access or leakage

Context​

  • Usage of PHP 7.0+ for server-side scripting and web development
  • Usage of Illuminate\Http\Request for handling HTTP requests in Laravel
  • Usage of the User module in the App namespace

Description​

Non compliant code​

<?php

namespace App\\Http\\Controllers;

use Illuminate\\Http\\Request;
use App\\User;

class UserController extends Controller
{
    public function index()
    {
        $users = User::all();
        return view('user.index', ['users' => $users]);
    }
}

The code above is vulnerable to a business information leak. The UserController retrieves all the user data from the database and sends it to the view. This data includes sensitive business information like usernames, employee information, client information, and provider information.

In the view file user.index, all the retrieved user data is displayed in an unordered list. This data includes sensitive business information like usernames, employee information, client information, and provider information.

This information leak vulnerability can lead to serious business impacts such as identity theft, phishing attacks, and other forms of fraud. It could also lead to a loss of trust from clients and employees, and potential legal implications.

To fix this vulnerability, we need to limit the data that is retrieved from the database and displayed to the user. Only necessary information should be displayed, and any sensitive information should be kept secure and confidential.

Steps​

  • Implement access control to restrict who can view the user list. Only authorized users should be able to access this information.
  • Paginate the user list to limit the amount of data that can be obtained at once.
  • Remove sensitive information from the user model that is sent to the view. Only display necessary information.
  • Implement rate limiting to prevent automated attacks from scraping all user data.
  • Log and monitor access to the user list to identify potential data breaches.

Compliant code​

<?php

namespace App\\Http\\Controllers;

use Illuminate\\Http\\Request;
use App\\User;
use Illuminate\\Support\\Facades\\Auth;
use Illuminate\\Support\\Facades\\Log;

class UserController extends Controller
{
    public function __construct()
    {
        $this->middleware('auth');
        $this->middleware('can:view,user');
    }

    public function index()
    {
        if(Auth::check()){
            Log::info('User list viewed by ', ['user' => Auth::user()]);
            $users = User::paginate(10);
            return view('user.index', ['users' => $users]);
        } else {
            return redirect('login');
        }
    }
}

The updated code includes several security measures to prevent business information leakage:

  1. Access Control: The __construct() method now includes middleware for authentication and authorization. The auth middleware ensures that only logged-in users can access the user list. The can:view,user middleware checks if the authenticated user has the 'view' permission for 'user' resources.

  2. Pagination: The paginate(10) method is used to limit the number of users returned at once. This prevents an attacker from obtaining all user data in a single request.

  3. Authentication Check: The Auth::check() method is used to verify if the user is authenticated before allowing access to the user list. If the user is not authenticated, they are redirected to the login page.

  4. Logging: The Log::info() method is used to log every access to the user list. This includes the authenticated user's details, which can be used to identify potential data breaches.

Remember to update your User model to only include necessary information when converted to an array or JSON. You can do this by setting the $hidden property on the model:

protected $hidden = ['password', 'remember_token', 'other_sensitive_info'];

Also, consider implementing rate limiting on your routes to prevent automated attacks from scraping all user data. You can do this in Laravel by chaining the throttle middleware to your routes:

Route::middleware('auth:api', 'throttle:60,1')->group(function () {
    Route::get('/users', 'UserController@index');
});

This will limit requests to 60 per minute per user. Adjust the rate limit as necessary for your application.

References​

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