The importance of disabling the WordPress XML-RPC endpoint for website security

One of the less-talked-about vulnerabilities that can still expose your site to brute-force and other cyber attacks is the legacy XML-RPC endpoint. While modern plugins and themes have shifted to using the more secure and efficient RESTful API, many WordPress sites still have the XML-RPC functionality enabled, unknowingly leaving an additional doorway open for malicious activities.

# What is XML-RPC in WordPress?

XML-RPC is a remote procedure call (RPC) protocol that uses XML to encode its calls and HTTP as the transport mechanism. In the early days of WordPress, this protocol was essential for enabling remote access to websites. It allowed third-party applications, like the official WordPress mobile app, to interact with your website by publishing content, managing comments, or handling other administrative functions.

However, times have changed. With the advent of the WordPress REST API, most modern tools and plugins no longer rely on XML-RPC for any legitimate purpose. The REST API offers a more secure, scalable, and flexible way to interact with WordPress websites.

# Why XML-RPC is a Security Risk

Leaving the XML-RPC endpoint enabled, particularly when it’s not being used, poses several significant security risks. Here’s why:

1. Brute-Force Attacks: One of the most common issues with XML-RPC is that it can be exploited for brute-force login attempts. The protocol allows attackers to try multiple username-password combinations in a single request, making brute-force attacks much more efficient compared to traditional login attempts. This method allows hackers to bypass some rate-limiting systems because it bundles the login requests.

2. Amplified Denial of Service (DoS) Attacks: XML-RPC can also be used in DoS attacks, particularly by exploiting its pingback.ping method. Attackers can send numerous pingback requests to a site, potentially overwhelming the server and causing it to crash or become unresponsive.

3. Data Exposure and Vulnerabilities: Over the years, several vulnerabilities have been discovered within the XML-RPC protocol. Even if they have been patched, leaving the endpoint enabled introduces an unnecessary risk to your website, especially when you’re not using it. Each open endpoint adds complexity to your security posture and increases the chances that a yet-undiscovered vulnerability could be exploited.

# Why You Should Disable XML-RPC

If you're not using any tools that rely on XML-RPC (and most modern WordPress sites do not), it’s wise to disable this legacy feature entirely. Disabling it helps close off an unnecessary attack vector, strengthening your website’s security.

Even if you're not facing brute-force attacks today, proactive security measures can prevent future incidents. Disabling the XML-RPC endpoint is a straightforward and effective way to reduce your website’s attack surface and focus on more modern, secure methods like the REST API.

# Conclusion

In today’s environment, website security is no longer optional — it’s essential. The legacy WordPress XML-RPC endpoint is an often-overlooked door that, when left open, can expose your site to various forms of attack. Given that modern WordPress plugins and themes prefer the more secure and flexible RESTful API, there’s little reason to keep this outdated endpoint enabled. By disabling XML-RPC, you can close off a potential vulnerability and strengthen the security of your website.

Take proactive measures now to protect your WordPress site and disable XML-RPC if you're not using it. Your website and your users will be safer for it.