Lack of data validation - Out of range - PHP

Lack of data validation - Out of range - PHP

Need

Enforce proper data validation to prevent unauthorized access and bypassing of restrictions

Context

  • Usage of PHP 7.2 for server-side scripting and web development
  • Usage of Laravel Framework for PHP web application development
  • Usage of laravel/ui for scaffolding Laravel user interfaces
  • Usage of Laravel Passport for implementing OAuth2 authentication in Laravel applications

Description

Non compliant code

        Route::group(['prefix' => 'admin', 'middleware' => ['auth']], function () {
    Route::get('/employeeManagement', 'EmployeeController@index');
});
        
        

In the above code, we have a route group that is prefixed with admin and has a middleware for authentication. This means that only authenticated users can access the routes defined within this group.

However, the route /employeeManagement is directly accessible to any authenticated user, without any additional permission checks. This means that even if a user's role does not have permission to manage employees, they can still access this functionality by directly navigating to /admin/employeeManagement.

This is a vulnerability because it allows authenticated users to bypass the role-based access control (RBAC) and access functionalities that they are not supposed to.

This vulnerability can lead to unauthorized access and manipulation of data, which can have serious security implications. For example, an authenticated user without the necessary permissions could potentially view, create, update, or delete employee data.

This vulnerability is due to the lack of data validation. Specifically, the application does not validate whether the authenticated user has the necessary permissions to access the /employeeManagement route.

Steps

  • Implement role-based access control (RBAC) to restrict access to certain functionalities based on user roles.
  • In the middleware, check the role of the authenticated user before granting access to the restricted functionalities.
  • If the user does not have the required role, return an error message or redirect them to an unauthorized access page.
  • Avoid using absolute paths to functionalities. Instead, use relative paths and validate the path in the server-side code.
  • Regularly update and patch the server and application to prevent bypassing of restrictions.

Compliant code

        Route::group(['prefix' => 'admin', 'middleware' => ['auth', 'role:admin']], function () {
    Route::get('/employeeManagement', 'EmployeeController@index');
});
        
        

The code above is a Laravel route group that applies middleware to a group of routes. The middleware 'auth' is used to ensure that the user is authenticated before they can access the routes within the group.

The vulnerability in the previous code was that it lacked role-based access control (RBAC). This means that any authenticated user could access the routes within the group, even if they were not supposed to have access to these functionalities.

To fix this vulnerability, we added another middleware 'role:admin' to the route group. This middleware checks if the authenticated user has the 'admin' role before they can access the routes within the group. If the user does not have the 'admin' role, they will be redirected to an unauthorized access page.

In addition, we are no longer using absolute paths to functionalities. Instead, we are using relative paths and validating the path in the server-side code. This prevents users from bypassing restrictions by using absolute paths.

Finally, it is important to regularly update and patch the server and application to prevent bypassing of restrictions. This includes updating the Laravel framework and any dependencies, as well as regularly reviewing and updating the server configuration and security settings.

References