NinjaFirewall (WP Edition)


A true Web Application Firewall

NinjaFirewall (WP Edition) is a true Web Application Firewall. Although it can be installed and configured just like a plugin, it is a stand-alone firewall that sits in front of WordPress.

It allows any blog administrator to benefit from very advanced and powerful security features that usually aren’t available at the WordPress level, but only in security applications such as the Apache ModSecurity module or the PHP Suhosin extension.

NinjaFirewall requires at least PHP 5.3 (5.4 or higher recommended to use all its features) or HHVM 3.4+, MySQLi extension and is only compatible with Unix-like OS (Linux, BSD). It is not compatible with Microsoft Windows.

NinjaFirewall can hook, scan, sanitise or reject any HTTP/HTTPS request sent to a PHP script before it reaches WordPress or any of its plugins. All scripts located inside the blog installation directories and sub-directories will be protected, including those that aren’t part of the WordPress package. Even encoded PHP scripts, hackers shell scripts and backdoors will be filtered by NinjaFirewall.

Powerful filtering engine

NinjaFirewall includes the most powerful filtering engine available in a WordPress plugin. Its most important feature is its ability to normalize and transform data from incoming HTTP requests which allows it to detect Web Application Firewall evasion techniques and obfuscation tactics used by hackers, as well as to support and decode a large set of encodings. See our blog for a full description: An introduction to NinjaFirewall filtering engine.

Fastest and most efficient brute-force attack protection for WordPress

By processing incoming HTTP requests before your blog and any of its plugins, NinjaFirewall is the only plugin for WordPress able to protect it against very large brute-force attacks, including distributed attacks coming from several thousands of different IPs.

See our benchmarks and stress-tests: Brute-force attack detection plugins comparison

The protection applies to the wp-login.php script but can be extended to the xmlrpc.php one. The incident can also be written to the server AUTH log, which can be useful to the system administrator for monitoring purposes or banning IPs at the server level (e.g., Fail2ban).

Real-time detection

File Guard real-time detection is a totally unique feature provided by NinjaFirewall: it can detect, in real-time, any access to a PHP file that was recently modified or created, and alert you about this. If a hacker uploaded a shell script to your site (or injected a backdoor into an already existing file) and tried to directly access that file using his browser or a script, NinjaFirewall would hook the HTTP request and immediately detect that the file was recently modified or created. It would send you an alert with all details (script name, IP, request, date and time).

File integrity monitoring

File Check lets you perform file integrity monitoring by scanning your website hourly, twicedaily or daily. Any modification made to a file will be detected: file content, file permissions, file ownership, timestamp as well as file creation and deletion.

Watch your website traffic in real time

Live Log lets you watch your website traffic in real time. It displays connections in a format similar to the one used by most HTTP server logs. Because it communicates directly with the firewall, i.e., without loading WordPress, Live Log is fast, light and it will not affect your server load, even if you set its refresh rate to the lowest value.

Events Notification

NinjaFirewall can alert you by email on specific events triggered within your blog. Some of those alerts are enabled by default and it is highly recommended to keep them enabled. It is not unusual for a hacker, after breaking into your WordPress admin console, to install or just to upload a backdoored plugin or theme in order to take full control of your website.

Monitored events:

  • Administrator login.
  • Modification of any administrator account in the database.
  • Plugins upload, installation, (de)activation, update, deletion.
  • Themes upload, installation, activation, deletion.
  • WordPress update.

Anti-Malware Scanner

It allows you to scan your website for malware. The scanning engine is compatible with the popular Linux Malware Detect LMD (whose anti-malware signatures are included with this release) and with some ClamAV signatures as well. You can even write your own anti-malware signatures. See our blog for more details about that: Adding your own signatures to NinjaFirewall Anti-Malware

Stay protected against the latest WordPress security vulnerabilities

To get the most efficient protection, NinjaFirewall can automatically update its security rules daily, twice daily or even hourly. Each time a new vulnerability is found in WordPress or one of its plugins/themes, a new set of security rules will be made available to protect your blog immediately.

Strong Privacy

Unlike a Cloud Web Application Firewall, or Cloud WAF, NinjaFirewall works and filters the traffic on your own server and infrastructure. That means that your sensitive data (contact form messages, customers credit card number, login credentials etc) remains on your server and is not routed through a third-party company’s servers, which could pose unnecessary risks (e.g., employees accessing your data or logs in plain text, theft of private information, man-in-the-middle attack etc).

IPv6 compatibility

IPv6 compatibility is a mandatory feature for a security plugin: if it supports only IPv4, hackers can easily bypass the plugin by using an IPv6. NinjaFirewall natively supports IPv4 and IPv6 protocols, for both public and private addresses.

Multi-site support

NinjaFirewall is multi-site compatible. It will protect all sites from your network and its configuration interface will be accessible only to the Super Admin from the network main site.

Possibility to prepend your own PHP code to the firewall

You can prepend your own PHP code to the firewall with the help of an optional distributed configuration file. It will be processed before WordPress and all its plugins are loaded. This is a very powerful feature, and there is almost no limit to what you can do: add your own security rules, manipulate HTTP requests, variables etc.

Low Footprint Firewall

NinjaFirewall is very fast, optimised, compact, and requires very low system resource.
See for yourself: download and install Query Monitor and Xdebug Profiler and compare NinjaFirewall performances with other security plugins.

Non-Intrusive User Interface

NinjaFirewall looks and feels like a built-in WordPress feature. It does not contain intrusive banners, warnings or flashy colors. It uses the WordPress simple and clean interface and is also smartphone-friendly.

Ayuda contextual

Each NinjaFirewall menu page has a contextual help screen with useful information about how to use and configure it.
If you need help, click on the Help menu tab located in the upper right corner of each page in your admin panel.

Need more security ?

Check out our new supercharged edition: NinjaFirewall WP+ Edition

  • Unix shared memory use for inter-process communication and blazing fast performances.
  • IP-based Access Control.
  • Role-based Access Control.
  • Country-based Access Control via geolocation.
  • URL-based Access Control.
  • Bot-based Access Control.
  • Centralized Logging.
  • Antispam for comment and user regisration forms.
  • Rate limiting option to block aggressive bots, crawlers, web scrapers and HTTP attacks.
  • Response body filter to scan the output of the HTML page right before it is sent to your visitors browser.
  • Better File uploads management.
  • Better logs management.
  • Syslog logging.

Learn more about the WP+ Edition unique features. Compare the WP and WP+ Editions.


  • WordPress 3.3+
  • PHP 5.3+ (5.4 or higher recommended) or HHVM 3.4+
  • MySQL or MariaDB with MySQLi extension
  • Apache / Nginx / LiteSpeed compatible
  • Unix-like operating systems only (Linux, BSD etc). NinjaFirewall is NOT compatible with Microsoft Windows.


  • Overview page.
  • Statistics and benchmarks page.
  • Options page.
  • Policies pages: NinjaFirewall has a large list of powerful and unique policies that you can tweak accordingly to your needs.
  • Contextual help.
  • Event notifications can alert you by email on specific events triggered within your blog.
  • Login page protection: the fastest and most efficient brute-force attack protection for WordPress.
  • Live Log: lets you watch your website traffic in real time. It is fast, light and it does not affect your server load.
  • Firewall Log.
  • Dashboard widget.
  • File Guard: this is a totally unique feature, because it can detect, in real-time, any access to a PHP file that was recently modified or created, and alert you about this.
  • Network.
  • Rules Editor.
  • File Check: lets you perform file integrity monitoring upon request or on a specific interval (hourly, twicedaily, daily).
  • Security rules updates.
  • Anti-Malware.


  1. Upload ninjafirewall folder to the /wp-content/plugins/ directory.
  2. Activa el plugin desde el menú ‘Plugins’ de WordPress.
  3. Plugin settings are located in ‘NinjaFirewall’ menu.

Preguntas frecuentes

Installation Instructions
  1. Upload ninjafirewall folder to the /wp-content/plugins/ directory.
  2. Activa el plugin desde el menú ‘Plugins’ de WordPress.
  3. Plugin settings are located in ‘NinjaFirewall’ menu.
Why is NinjaFirewall different from other security plugins for WordPress ?

NinjaFirewall sits between the attacker and WordPress. It can filter requests before they reach your blog and any of its plugins. This is how it works :

Attacker > HTTP server > PHP > NinjaFirewall > WordPress

And this is how all WordPress plugins work :

Attacker > HTTP server > PHP > WordPress > Plugins

Unlike other security plugins, it will protect all PHP scripts, including those that aren’t part of the WordPress package.

How powerful is NinjaFirewall?

NinjaFirewall includes a very powerful filtering engine which can detect Web Application Firewall evasion techniques and obfuscation tactics used by hackers, as well as support and decode a large set of encodings. See our blog for a full description: An introduction to NinjaFirewall 3.0 filtering engine.

Do I need root privileges to install NinjaFirewall ?

NinjaFirewall does not require any root privilege and is fully compatible with shared hosting accounts. You can install it from your WordPress admin console, just like a regular plugin.

Does it work with Nginx ?

NinjaFirewall works with Nginx and others Unix-based HTTP servers (Apache, LiteSpeed etc). Its installer will detect it.

Do I need to alter my PHP scripts ?

You do not need to make any modifications to your scripts. NinjaFirewall hooks all requests before they reach your scripts. It will even work with encoded scripts (ionCube, ZendGuard, SourceGuardian etc).

I moved my wp-config.php file to another directory. Will it work with NinjaFirewall ?

NinjaFirewall will look for the wp-config.php script in the current folder or, if it cannot find it, in the parent folder.

Will NinjaFirewall detect the correct IP of my visitors if I am behind a CDN service like Cloudflare ?

You can use an optional configuration file to tell NinjaFirewall which IP to use. Please follow these steps.

Will it slow down my site ?

Your visitors will not notice any difference with or without NinjaFirewall. From WordPress administration console, you can click “NinjaFirewall > Status” menu to see the benchmarks and statistics (the fastest, slowest and average time per request). NinjaFirewall is very fast, optimised, compact, requires very low system resources and outperforms all other security plugins.
By blocking dangerous requests and bots before WordPress is loaded, it will save bandwidth and reduce server load.

Is there any Microsoft Windows version ?

NinjaFirewall works on Unix-like servers only. There is no Microsoft Windows version and we do not expect to release any.



This is an absolute great firewall, an absolute must for every wordpress installation. Quite effective and fast. Professional, no nonsense work. It ought have one million installations.

Was great, but not anymore

It was a great plugin, but not any more.

Beware, if you install it and the plugin can’t find your php.ini, you’re in trouble.
It will create a php.ini file in root, as well as a .user.ini file.

Follow all the activation steps and after that you get: Firewall is not loaded.
Only solution is a very technical one, I couldn’t execute the steps.

Then deactivated and deleted the plugin.
Result: a white page instead of my website.
So I reinstalled and have a not-working plugin right now.

Don’t know why and what changed, but NinjaFirewall was great, with some statement in my .htaccess, and working out-of-the-box, but not any more.

This is the best

This is by far the best security plugin out there. You really don’t need anything else to protect your website!
5 stars

Best security plugins !

After tried many security plugins, I have found NinjaFirewall now, and so happy with it, this is the best one ever !

Thank you very much for this speed, easy, free and so nice plugin !

Great, slightly aggressive addition to security set-up

The only security plugin out of my four or five “door staff” which detected an attempted Apache Struts2 remote code execution. XSS and XFO protection plus CSP capability are only a few of the other features which make this quite indispensable. Login/brute force protection really can lock you out of your site inadvertently, though, so I am too scared to use that until I have raised the issue with support! If you have any error scanning problems, try disabling Sucuri first before re-trying.

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Colaboradores y desarrolladores

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Registro de cambios


  • [WP+ Edition] In addition to the firewall log, all events can also be redirected to the server Syslog. See our blog for more info:
  • For a better readability, the “Firewall Policies” page has been split into three parts: Basic, Intermediate and Advanced Policies.
  • The “Brute-force protection by NinjaFirewall” signature can be disabled in the “Login Protection” page.
  • Fixed a caching issue with the “Login Protection” page where changes were not immediately visible after the form submission if a PHP opcode cache was installed.
  • Fixed an issue where the French translation included in the package was not always loaded.
  • [WP+ Edition] Fixed a “Cannot use object of type WP_Error” PHP error in the Antispam.
  • [WP+ Edition] By default, the “Maximum allowed file size” policy will use the same value as the PHP upload_max_filesize directive or, if not available, it will be set to 10 megabytes.
  • [WP+ Edition] Updated IPv4/IPv6 GeoIP databases.
  • Minor fixes.