Swellfire

This plugin disables the XML-RPC API on a WordPress site running 3.5 or above and unsets the X-Pingback header.
Beginning in 3.5, XML-RPC is enabled by default. Additionally, the option to disable/enable XML-RPC was removed. For various reasons, site owners may wish to disable this functionality. This plugin provides an easy way to do so.

Disable XML-RPC & Unset X-Pingback

This plugin disables XML-RPC API in WordPress 3.5+, which is enabled by default.

Walter Ebert

This plugin does more than just using the <code>xmlrpc_enabled</code> hook, because that is only used “To disable XML-RPC methods that require authentication”.
Activating this plugin will also disable pingbacks, trackbacks, and Really Simple Discovery (RSD), because these rely on XML-RPC.
It works with any webserver, because it does not use the .htaccess file.
<h4>Testing the plugin</h4>
From the command line you can test if the plugin is working correctly using <a href="https://curl.haxx.se/" rel="nofollow ugc">cURL</a>. Replace the <code>example.com</code> link to match your website:
<pre><code>curl -d '<?xml version="1.0"?><methodCall><methodName>system.listMethods</methodName><params><param><value><string/></value></param></params></methodCall>' https://example.com/xmlrpc.php
</code></pre>
This should only return the following methods: 
– <code>system.multicall</code> 
– <code>system.listMethods</code> 
– <code>system.getCapabilities</code>

Remove XML-RPC Methods

Remove all WordPress methods from the XML-RPC API to increase security.

Disable XML-RPC & Unset X-Pingback vs Remove XML-RPC Methods