Disable XML-RPC

A Security Risk for WordPress Sites

Imagine discovering a hidden backdoor in your WordPress website, one that could invite unwelcome visitors. Surprised? This could be the case with XML-RPC, a feature you might have never heard of, but could be your site’s Achilles’ heel. In this article, we’ll dive into the world of XML-RPC. Why is it a potential threat? Why must WordPress owners consider disabling it? We’ll unravel the secrets of XML-RPC, weigh it’s pros and cons, and guide you through various methods to disable it.

The WordPress Connector

XML-RPC is a feature in WordPress that lets your website communicate with other apps and programs. Think of it like a universal translator – It helps WordPress understand and exchange information with different software, using a common format called XML. This is useful for things like updating your blog from a smartphone app or connecting your site to other web services. It’s like enabling your WordPress site to speak and understand the same language as many other tech tools, making it easier to manage your site and share content from different places or devices.

Technical Details

  • XML-RPC: XML Remote Procedure Call
  • It is an API (Application Programming Interface)
  • Uses XML (eXtensible Markup Language) to encode its calls
  • Uses HTTP as the transport mechanism. 

The Risks of XML-RPC in WordPress

While XML-RPC once played a pivotal role in the WordPress ecosystem, its persistence in modern WordPress sites can open doors to several risks.

To an attacker, XML-RPC can also be seen as a special language that can be used to ask your website questions. If XML-RPC is enabled, it’s like leaving the door to your website slightly ajar, allowing attackers to peek inside and gather information. They can ask questions like:

  • “What is the username and password for the administrator account?”
  • “What plugins are installed on this website?”
  • “What is the content of this website’s database?”

By default, XML-RPC is turned on and enabled

Here are the top 2 reasons why keeping XML-RPC enabled might be a gamble:

Brute-Force Attacks: Brute-force attacks are relentless attempts to uncover a user’s password by systematically trying a vast array of possible combinations. With XML-RPC enabled, attackers can leverage this protocol to launch a barrage of username and password combinations simultaneously. This is because XML-RPC permits multiple authentication attempts within a single request, rendering website-imposed request limitations ineffective.

  • Further compounding the risk, XML-RPC lacks inherent safeguards against brute-force assaults. Attackers can relentlessly test different credentials until they eventually strike gold, leaving user accounts vulnerable.

DDoS Attacks: XML-RPC can be used to perform Distributed Denial of Service (DDoS) attacks. DDoS attacks aim to overwhelm a website’s resources, rendering it inaccessible to legitimate users – crashing the site. By utilizing XML-RPC, attackers can flood the site with a multitude of requests with various methods or functions, including pingback.ping, system.multicall, and others. These requests consume a significant amount of server resources, ultimately incapacitating the site.

 

  • The effectiveness of DDoS attacks using XML-RPC lies in its ability to bypass server-imposed rate limits. XML-RPC allows for multiple requests within a single request, effectively circumventing any restrictions implemented by the website.
  • XML-RPC also lacks built-in protection against DDoS assaults. Attackers can repeatedly bombard a site with requests, steadily increasing the load on the server until it collapses.

The Advantages of Disabling XML-RPC

Disabling XML-RPC offers enhanced security, but it also offers significant performance for your WordPress site as well. By eliminating this protocol, you can protect your site from Brute-Force and DDoS attacks, as well as the following performance improvements.

Reduced Server Load: By disabling XML-RPC, you eliminate unnecessary traffic directed to your server, which can lead to decreased server load and improved performance. This is especially beneficial for sites with high traffic or limited server resources.

Optimized Resource Allocation: When XML-RPC is enabled, it consumes server resources, which could potentially affect other essential processes. Disabling XML-RPC frees up these resources, allowing your site to function more efficiently and handle other tasks smoothly.

The Potential Disadvantages of Disabling XML-RPC

Disabling XML-RPC in WordPress can have some drawbacks, especially if you use certain features or third-party apps. Here’s a breakdown of the potential disadvantages of disabling XML-RPC:

Reduced Plugin Functionality: Some plugins rely on XML-RPC to perform essential functions, such as remote publishing, media synchronization, or backup services. Disabling XML-RPC may render these plugins inoperable or cause them to function improperly.

Limited Third-Party Integrations: Certain third-party applications or services may utilize XML-RPC to communicate with your WordPress site. Disabling XML-RPC could disrupt these integrations, preventing seamless data exchange or functionality with these services.

Compatibility Issues: Some older plugins or themes may not function properly with XML-RPC disabled. This could require updates to these components or additional workarounds to ensure compatibility.

So, Should I Keep XML-RPC Enabled, or Not?

Despite the potential drawbacks, disabling XML-RPC is generally recommended for WordPress sites due to the significant security benefits it offers. While some plugins may rely on XML-RPC for functionality, the security advantages outweigh the potential inconveniences:

Reduced Plugin Vulnerabilities: Many older plugins that utilize XML-RPC may contain security vulnerabilities or outdated code, increasing the risk of exploits. By disabling XML-RPC, you mitigate the risk posed by these plugins and encourage developers to update or seek alternative solutions.

Promoting Modern Plugin Practices: Disabling XML-RPC encourages plugin developers to adopt more secure and modern authentication methods, such as REST API or OAuth. This shift promotes better security practices across the WordPress ecosystem and enhances the overall security of your site.

Alternative Solutions for XML-RPC Plugins: In most cases, there are alternative solutions or plugins that can provide the same functionality without relying on XML-RPC. For instance, many backup plugins now offer secure alternatives to remote post publishing, and there are reliable APIs for media synchronization.

For most WordPress site owners, disabling XML-RPC will not cause issues – Most plugins and applications do not rely on it, and there are alternative solutions available for those that do.

Methods to Disable XML-RPC

Now that we understand the advantages of disabling XML-RPC, let’s explore different methods to achieve this:

Method 1 – Using a Dedicated Plugin: There are several plugins available that can disable XML-RPC for you. This can be a convenient option if you’re not comfortable editing code.

  • One popular plugin for this purpose is Disable XML-RPC. This plugin is easy to use and will disable XML-RPC with just a few clicks.

Method 2 – Using a WordPress Security Plugin: Some WordPress security plugins offer the ability to disable XML-RPC as part of their security features. If you’re already using a WordPress security plugin, you may want to check if it has this option.

  • For example, the plugin Wordfence includes a feature that can disable XML-RPC authentication.
  • Follow these simple instructions to disable XML-RPC with Wordfence:
    • Install and activate the Wordfence plugin
    • Go to the Login Security section and enable the Disable XML-RPC Authentication option

Method 3 – Editing Your Site’s functions.php File: This method involves adding a simple code snippet to your site’s functions.php file. This code snippet will instruct WordPress to disable XML-RPC functionality:

add_filter( ‘xmlrpc_enabled’, ‘__return_false’ );

  • Place this code snippet at the end of your functions.php file and save the changes. This will immediately disable XML-RPC on your site.

Other options are available to disable XML-RPC in WordPress – Feel free to check out wpbeginner’s Blog for further knowledge and options!

Conclusion

XML-RPC is a legacy protocol that was once commonly used for communication between WordPress sites and external applications. However, it has become increasingly vulnerable to security breaches and is no longer considered essential for most WordPress sites. Disabling XML-RPC is a recommended security practice that can significantly reduce the risk of brute-force attacks, DDoS attacks, and other exploits.

While disabling XML-RPC may require some adjustments to plugins or workflows, the security benefits far outweigh the potential inconveniences. Modern plugin practices and alternative solutions are often available, making it easier to maintain a secure and functional WordPress site without relying on XML-RPC.

For business owners, disabling XML-RPC is a proactive measure that protects their online presence and safeguards their valuable data. By prioritizing security and adopting modern plugin practices, businesses can ensure their WordPress sites remain protected in the ever-evolving cyber landscape.

Want to see XML-RPC being exploited? Check out this blog post by Lucian Nitescu: Exploiting the XML-RPC PHP on All WordPress Versions

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