WAF for WordPress

Stop real-life attacks on your WordPress website and trigger Fail2Ban.

This WAF does not give proper HTTP responses to unusual requets. It blocks the attacking IP address instantly, the purpose of this are the following.

Prevent website compromise in further requests
Prevent D/DoS attacks

Shared hosting has no server-wide banning (because of trust issues) but you can still install this software without Fail2Ban to stop attacks by using one of the Miniban methods.

Theory

Your WordPress - really general HTTP - security consists of:

Use HTTPS
Have daily backups
Block known hostile networks
Have Fail2Ban installed (controls the firewall)
Maintain your website and use strict Fail2Ban filters which ban on the first suspicious request instantly
Deny direct access to core WordPress files, themes and plugins
Install WAF for WordPress (this project)
Use Leanmail for filtering Fail2Ban notification emails

See the Block WordPress attack vectors note in my other repository for an overview of the topic.

Composer installation

Technically this is not a WordPress plugin nor an MU plugin. WAF for WordPress is distributed and autoloaded as a Composer package.

Issue composer require szepeviktor/waf4wordpress command
Load vendor/autoload.php from your wp-config

Instantiate SzepeViktor\WordPress\Waf\HttpAnalyzer class early in wp-config

require dirname(__DIR__) . '/vendor/autoload.php';
new \SzepeViktor\WordPress\Waf\Components\HttpAnalyzer();

Create an MU plugin in wp-content/mu-plugins/waf4wordpress.php

<?php
/*
 * Plugin Name: WAF for WordPress (MU)
 */
if (! function_exists('add_filter')) {
    exit;
}
new \SzepeViktor\WordPress\Waf\Components\CoreEvents();

Manual installation

💡 Please see Composer-managed WordPress for managing WordPress with Composer.

Technically this is not a WordPress plugin nor an MU plugin.

First download WAF for WordPress then extract files to a directory, e.g. waf/

Instantiate SzepeViktor\WordPress\Waf\HttpAnalyzer class early in wp-config

require_once __DIR__ . '/waf/src/HttpAnalyzer.php';
require_once __DIR__ . '/waf/src/CoreEvents.php';
new \SzepeViktor\WordPress\Waf\Components\HttpAnalyzer();

Create an MU plugin in wp-content/mu-plugins/waf4wordpress.php

<?php
/*
 * Plugin Name: WAF for WordPress (MU)
 */
if (! function_exists('add_filter')) {
    exit;
}
new \SzepeViktor\WordPress\Waf\Components\CoreEvents();

Configuration

WAF for WordPress is configured in source code before class instantiation. in wp-config.

Create custom filters for Fail2Ban catching these PHP messages.

Likely malicious requests: Malicious traffic detected: may be banned after 6 attempts per 10 minutes
Surely break-in attempts: Break-in attempt detected: may be banned instantly

How to support PayPal IPN, Braintree and custom entry points in poorly written plugins

Copy this into your in wp-config.php.

// Enable PayPal IPN in WooCommerce
if ( isset( $_SERVER['REQUEST_URI'] ) ) {
    if ( '/wc-api/WC_Gateway_Paypal/' === parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH ) ) {
        // PayPal IPN does not send Accept: and User-Agent: headers
        $_SERVER['HTTP_ACCEPT'] = '*/*';
        $_SERVER['HTTP_USER_AGENT'] = 'Mozilla/5.0 PayPal/IPN';
    }
}

// Enable Braintree Webhooks
new \Waf4WordPress\Braintree_Fix( '/braintree/webhook' );

// Enable email opens in Newsletter plugin
if ( isset( $_SERVER['REQUEST_URI'] ) ) {
    $newsletter_path = parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH );
    if ( '/wp-content/plugins/newsletter/statistics/open.php' === $newsletter_path
        || '/wp-content/plugins/newsletter/statistics/link.php' === $newsletter_path
    ) {
        // UA hack for old email clients
        $_SERVER['HTTP_USER_AGENT'] = 'Mozilla/5.0 ' . $_SERVER['HTTP_USER_AGENT'];
    }
    unset( $newsletter_path );
}

// Enable email open tracking in ALO EasyMail Newsletter plugin
if ( isset( $_SERVER['REQUEST_URI'] ) ) {
    $alo_path = parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH );
    if ( '/wp-content/plugins/alo-easymail/tr.php' === $alo_path ) {
        // UA hack for old email clients
        $_SERVER['HTTP_USER_AGENT'] = 'Mozilla/5.0 ' . $_SERVER['HTTP_USER_AGENT'];
    }
    unset( $alo_path );
}

Support and feature requests

Open a new issue

Where script kiddies look for WordPress

/backup/
/blog/
/cms/
/demo/
/dev/
/home/
/main/
/new/
/old/
/portal/
/site/
/test/
/tmp/
/web/
/wordpress/
/wp/

Best not to create these directories to avoid lenghty log excepts.

saas786 / waf4wordpress