Basic Firewall Bypass Prevention for Apache Web Servers

This is not a guaranteed way to stop attempts to bypass your firewall but will stop a very large majority of rookie attempts to make direct requests.

Apache web server and Nginx reverse proxy are widely used components in web infrastructure. This solution focuses on integrating preventative measures into your Apache configuration.

Leveraging Headers from CDNs and Firewalls is a common practice among web applications today. Larger content delivery networks (CDNs) and firewalls often include additional headers when forwarding requests to your server. By requiring these headers in incoming requests, we can effectively deter automated attackers who typically lack the capability to modify requests with the appropriate headers.

The .htaccess file, located in the web root directory of your application (e.g., public_html/.htaccess), plays a crucial role in implementing this prevention mechanism. By adding specific rewrite conditions to validate the headers, we can control access to your web application. Follow the steps below to apply this solution:

1. Open the .htaccess file using a text editor.
2. Add the following code snippet, replacing “defaultdomain.com” with your domain and “HEADER-GOES-HERE” with the appropriate header used by your firewall:

# BEGIN Website Firewall Bypass Prevention
RewriteEngine On
RewriteCond %{HTTP_HOST} ^(www\.)?defaultdomain.com$
RewriteCond %{HTTP:HEADER-GOES-HERE} ^$
RewriteRule ^(.*)$ - [F,L]
ErrorDocument 403 Forbidden
# END Website Firewall Bypass Prevention

3. Save the changes to the .htaccess file.

4. Restarting Apache and Nginx To ensure the changes take effect and clear any existing cache, restart both the Apache web server and Nginx reverse proxy.

By following these simple steps, you can significantly reduce the likelihood of rookie attempts to bypass your firewall. Remember that no solution is foolproof, and it’s essential to regularly update and maintain your web server’s security measures to stay ahead of potential threats.

Note: It’s important to keep in mind that the effectiveness of this prevention method may vary depending on your specific environment and the sophistication of attackers.