Sysadmins of the North

Technical blog, where topics include: computer, server, web, sysadmin, MySQL, database, virtualization, optimization and security

Category: WordPress Security

WordPress security is a topic of huge importance for every WordPress developer and website owner. Harden your WordPress website security with these valuable tips!

How to: Protect WordPress from brute-force XML-RPC attacks

The WordPress XML-RPC API has been under attack for many years now. Back in August 2014, WordPress released version 3.9.2, fixing a possible denial of service issue in PHP’s XML processing. There are brute-force amplification attacks, reported by Sucuri, and so on. So, how do you protect WordPress from xmlrpc.php attacks, but still being able to use (some of) its functionality like Jetpack? This post gives you some insight.

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Check WordPress Core files integrity

Check the md5 checksum of WordPress Core files against WordPress’ checksums API, using this standalone PHP file. I chose to use a standalone PHP script to check the md5sum of WordPress Core files against the API so you’re not dependent on a possibly hacked WordPress installation. This kind of guarantees the result can be trusted, as opposed to using a WordPress plugin. I think this is a better integrity check of WordPress Core files.

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WordPress advisory: Akal premium theme XSS vulnerability & abandonded

Over the course of one week I had the opportunity to audit two hacked WordPress websites. I could quickly discover two vulnerabilities: a Cross Site Scripting, or XSS, in a premium WordPress theme Akal, and a Denial-of-Service in an undisclosed newsletter plugin. This post describes the Akal premium WordPress theme XSS vulnerability.

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Add a delay to your WordPress login form

It is important to protect your WordPress website from brute-force attacks, and various security plugins exist in doing so. For the purpose of this article, I modified the WordPress Login Delay plugin with a fixed delay of three seconds for my wp-login.php page. This provides you with an easy to use method of protecting your WordPress login form (but do read the caveats!).

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WordPress Plugin Vulnerability Dump – Part 1

This post contains information on vulnerabilities for 7 (at least somewhat) popular WordPress plugins. All of these vulnerabilities were trivial to discover (and are trivial to fix). The state of WordPress plugin security is very sad indeed. None of the developers were contacted in advance of this post (except where otherwise noted). Additional vulnerabilities will be posted as time permits. WordPress Plugin Vulnerability Dump – Part 1

Send authenticated SMTP email over TLS from WordPress

How to configure TLS for SMTP email in WordPress. I was suprised WordPress is not able to send email using an SMTP server out-of-the-box. Not to mention using authenticated SMTP or TLS transport for security. A quick Google search showed me multiple plugins to handle this, but I wanted to create something myself. Here is how to override the wp-mail() function and send email using authenticated SMTP and StartTLS from WordPress.

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Huge increase in WordPress xmlrpc.php POST requests

WordPress xmlprc.php DDoS and brute-force attacks. How to identify, block, mitigate and leverage these xmlrpc.php scans, brute-force, and user enumeration attacks on WordPress sites… Secure WordPress xmlprc.php interface and reduce service disruption.

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Block WordPress comment spammers manually

The less spammers hit your WordPress blog, the better your blog performs, is one of my opinions. A second is, the less unnecessary plugins you use on your WordPress blog, the better. So, a little while ago I decided to remove plugins like Stop Spammer Registration Plugin and do its work myself. Here is why & how:

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Secure WordPress with a Captcha

update 2017-12-20: watch out for a Captcha version with a backdoor! WordPress security can be improved with plugins. Also from brute-force login attempts. Lately, a lot of brute force attacks are targeted against WordPress websites.

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