how to block xmlrpc attacks in WordPress

Understanding XML-RPC in WordPress

XML-RPC (XML Remote Procedure Call) is a protocol that uses XML to encode its calls and HTTP as a transport mechanism. Originally designed to facilitate communication between systems, in WordPress, XML-RPC enables data transmission, with features like remote post creation and management. Although its capabilities are powerful, XML-RPC also presents a significant security vulnerability in WordPress.

Identifying XML-RPC Attacks

XML-RPC attacks often manifest as brute-force attacks. Attackers use this protocol to try various username and password combinations to gain unauthorized access to your site. They can also initiate DDoS attacks, sending a high volume of requests to your server, thus exhausting the resources.

Blocking XML-RPC Attacks: A Step-by-Step Guide

Step 1: Disable XML-RPC Completely

If you don’t need XML-RPC functionality, the best way to secure your WordPress site is by completely disabling it. You can do this via a plugin or manually via the .htaccess file.

Using a Plugin:

• Use plugins like ‘Disable XML-RPC’ which turn off this feature without modifying any files. Install the plugin and activate it; the rest is handled automatically.

Manually via .htaccess:

• Connect to your site using FTP and edit the .htaccess file located in your WordPress root directory.
• Add the following code:

  # Block WordPress xmlrpc.php requests
  
  order deny,allow
  deny from all
  

  This method blocks all access to xmlrpc.php, preventing any XML-RPC related request.

Step 2: Limit XML-RPC Functionality

If some of your site features require XML-RPC, consider limiting its functionality rather than disabling it completely.

Using Plugins:

• Install a security plugin that offers granular control over XML-RPC functionalities. Plugins like ‘WordFence’ or ‘All in One WP Security & Firewall’ can block XML-RPC methods that permit authentication, reducing the risk of brute-force attacks.

Step 3: Restrict Access by IP

If your XML-RPC needs to be accessible but only by specific IPs (like from a mobile app or a specific network), you can set up IP restrictions.

• Modify the .htaccess file to permit only specified IP addresses.

  
  order deny,allow
  deny from all
  allow from 123.123.123.123
  

  Replace 123.123.123.123 with the IP address that requires access.

Step 4: Use a Firewall

A Web Application Firewall (WAF) can be helpful in blocking not just XML-RPC attacks but a myriad of other threats.

• Services like Cloudflare or Sucuri offer WAF features that detect and block malicious traffic before it reaches your site. These services can be configured to recognize patterns typical of XML-RPC attacks and prevent them accordingly.

• Configure the WAF settings to specifically target and block XML-RPC attack patterns like high-frequency requests from the same IP address.

Step 5: Monitor and Audit Regularly

Constant monitoring can help you respond to attacks before they cause significant damage.

• Use security plugins to keep an eye on the site’s activity. These plugins usually come with logging features that record all requests to xmlrpc.php.

• Regular audits of these logs can help you identify unusual activities and patterns that might signify an attack, allowing you to take preemptive action.

Best Practices

1. Keep WordPress Updated: Always ensure your WordPress core, plugins, and themes are up to date. Updates often contain patches for known vulnerabilities, including XML-RPC.

2. Strong Passwords: Implement strong password policies to enhance your defense against brute-force attacks.

3. Use HTTPS: Secure your site with SSL/TLS, ensuring that data sent and received is encrypted, providing another layer of security.

XML-RPC functionality poses both utilities and threats, understanding how to manage and secure this feature is paramount in ensuring your WordPress site’s security. Properly securing XML-RPC involves assessing your requirements, implementing one or more of the outlined methods, and maintaining security vigilance through regular monitoring. This proactive approach to security helps mitigate risks and protect your site from potential attacks.