DNS rebinding is a type of attack that exploits the trust between a browser and its internal network, potentially exposing sensitive data or enabling unauthorized access to private systems. Laravel applications can be vulnerable to DNS rebinding if security measures are not properly configured.
In this blog post, we’ll explore DNS rebinding vulnerabilities, show how to mitigate them in Laravel and provide coding examples to strengthen your application’s defenses.
If you’re unsure about your website’s current security, try our Free Website Security Scanner tool to get an instant report.
DNS rebinding exploits the browser's ability to resolve domain names into IP addresses. By maliciously resolving a domain to an attacker-controlled IP address, the attacker can interact with services or APIs on the victim’s internal network.
DNS rebinding attacks can expose APIs or internal systems behind your Laravel app to unauthorized users. This could result in data leaks, code execution, or unauthorized system access.
1. Validate Host Headers
Laravel applications should validate the Host header to ensure the request originates from trusted domains.
Here’s how to do it:
<?php
// Add this to your middleware to validate the Host header
namespace App\Http\Middleware;
use Closure;
use Illuminate\Http\Request;
class ValidateHostHeader
{
public function handle(Request $request, Closure $next)
{
$trustedHosts = ['yourdomain.com', 'www.yourdomain.com'];
if (!in_array($request->getHost(), $trustedHosts)) {
abort(403, 'Unauthorized request');
}
return $next($request);
}
}
?>
2. Restrict Internal Network Access
Limit the scope of allowed IP addresses when your application interacts with external APIs. Use Laravel’s built-in Gate feature for this purpose.
<?php
// Define a Gate to restrict access based on IP
use Illuminate\Support\Facades\Gate;
Gate::define('allow-api-access', function ($user, $ip) {
$allowedIPs = ['192.168.1.1', '192.168.1.2'];
return in_array($ip, $allowedIPs);
});
?>
DNS pinning ensures that your Laravel application interacts only with specific IP addresses for known domains.
<?php
// DNS Pinning Implementation
use Illuminate\Support\Facades\Http;
$response = Http::withOptions([
'base_uri' => 'https://example.com',
'resolve' => [
'example.com' => '93.184.216.34', // Resolve the domain to a fixed IP
]
])->get('/api/data');
?>
Laravel’s ecosystem provides several packages to protect against DNS rebinding. For instance:
Use spatie/laravel-csp to enforce Content Security Policies.
Configure Laravel Sanctum for API security and session management.
To check if your Laravel application is vulnerable to DNS rebinding or other security flaws, use our Website Security Checker tool.
Screenshot of Our Free Website Security Tool
Below is a screenshot of our tool that can instantly assess vulnerabilities in your website:
Screenshot of the free tools webpage where you can access security assessment tools.
After scanning your website with our tool to check Website Vulnerability, you’ll receive a detailed vulnerability assessment report. Below is an example of what the report looks like:
An Example of a vulnerability assessment report generated with our free tool, providing insights into possible vulnerabilities.
DNS rebinding is a stealthy attack, but it can be effectively mitigated by validating host headers, restricting network access, and implementing DNS pinning. Following best practices in Laravel ensures a secure application environment for your users.
For more insights on securing Laravel applications and other cybersecurity tips, check out our Pentest Testing Corp Blog.
By taking these measures, you’ll protect your Laravel application and enhance your users' trust.