What is XMLRPC?
The name tells you everything you need to know about the functionality.
XML - XML was designed to accept XML payloads. JSON is now a much more common format. XMLRPC predates JSON by quite a bit.
RPC – RPC stands for Remote Procedure Call. It was a standard by which one system could ask another system to do something. Now we use REST APIs or Graph APIs – to do the same thing, but before those existed, RPC was one of the tools available.
How does XMLRPC work?
To get XMLRPC.php to do something, you had to POST a message to it. If you're not familiar with how browsers work, this is basically like clicking the "Submit" button on a form. That usually initiates a POST request.
If you make a POST request to yourdomain.tld/xmlrpc.php and give it a properly formatted XML payload, you can do things like create a post on your website.
One of the things XMLRPC was used a lot for back in the day was “pingbacks.” Those comments you see on posts that show someone else linked to it from their blog.
WordPress XMLRPC Potential Security Threats
For a long time, XMLRPC was a useful tool. Now all the functionality that XMLRPC was used for is handled by the built-in REST API. Even though it is no longer used, it is still an active feature and those who are nostalgic for such things will smile. However, those who are concerned about security will look at it and frown.
The presence of XMLRPC poses several security risks to WordPress sites that qatar whatsapp number data can escalate into severe attacks.
Brute force attacks via XMLRPC
The first type of WordPress XMLRPC attack is a simple brute force attack. Since part of the XML payload passed to WordPress is the username and password of the user who wants to perform the action, it's an easy way for attackers to try out username and password combinations until they find one that works. Many security-conscious site owners will limit the number of login attempts a user can make before locking them out, but won't bother blocking XMLRPC requests, leaving a backdoor open for attackers to try and find a way in.
Once an attacker finds working credentials, they can attempt to harm your site by injecting content into your site's database. Whether it's posts, pages, or just comments, the end result is the same: your site is serving content you didn't approve of and probably don't want. However, in the worst case scenario, these could be harmless posts or comments that have malware injected into them.
DDoS attacks using XMLRPC
Another benefit of XMLRPC was the enabling of pingbacks. Cybercriminals can use this to crash your server by issuing many heavy requests at once.
