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NGINX App Protect, ModSecurity WAF, and open-appsec Compared

As web applications play a critical role in modern businesses, ensuring they’re secure is of utmost importance. And so, to defend against cyber threats, many organizations rely on Web Application Firewalls (WAFs) to provide an extra layer of security.

In this article, we will compare three WAF solutions – NGINX App Protect, ModSecurity WAF, and open-appsec WAF.

We will explore their similarities and differences in features, performance, ease of use, and more, to help you decide which WAF solution is right for your organization.

Whether you're a seasoned security professional or just starting your research, this article will provide valuable insights into these three WAF solutions.

Difference Between NGINX App Protect, ModSecurity WAF, and open-appsec WAF


NGINX App Protect WAF

ModSecurity WAF

open-appsec WAF


It is not an open-source application security solution.

It is an open-source solution.

It is an open-source solution, and a third party has independently verified its source code.

Ease of configuration

Relatively simple to configure but requires on-going tuning.

A beginner might find it difficult to configure.

It is easy to configure.

False positives




WAF community and customer service

It has a medium-sized community.

It has a large community of users and developers.

open-appsec WAF is a relatively new solution and has a smaller community. However, the small community size means it's easy to get help from an administrator if you encounter any issues when using the solution.

Machine-learning WAF approach

Doesn’t use machine learning to protect web applications.

Does not rely on machine learning for web application security.

It uses machine learning to offer more effective protection for your web app.

Zero-day protection




Similarities between NGINX App Protect, ModSecurity WAF, and open-appsec WAF

  1. All three solutions protect against web application security threats, such as SQL injection, cross-site scripting (XSS), and malicious file uploads.

  2. All three solutions can integrate with the NGINX web server to provide enhanced security for web applications.

  3. They provide real-time protection against security threats, preventing attackers from compromising web applications.

  4. All three solutions can be easily configured and customized to meet specific security needs.

  5. They provide scalable protection for web applications, regardless of size or complexity.

  6. All three solutions are designed to have minimal impact on performance, allowing web applications to operate efficiently.

NGINX APP Protect Web Application Firewall

NGINX App Protect is a WAF that helps keep your web application firewall safe from malicious attacks. It uses policies to defend your web apps from SQLi, XSS, DDoS, and other web attacks.

Additionally, the NGINX App Protect acts as a load balancer, content cache, web server, and API gateway to create a strong protective barrier for your applications. It works seamlessly in all DevOps environments as a WAF or an app-level DoS defense for your web apps.

Below are two of its most outstanding features.

Features of the NGINX App Protect WAF

  • Large request blocking

Since a large request can exhaust your web app's CPU time, memory, and disk space and make it susceptible to brute-force attacks, the NGINX App Protect blocks web requests that are more than 10MB, including file uploads. It automatically disallows the access of 30+ notoriously malicious file types like .wmz, .p7b, .bak, etc., and also allows you to customize this default setting to help reduce the chances of false positives.

  • XML, gRPC, and JSON content monitoring and parsing

XML, gRPC, and JSON all share the common functionality of transmitting data and communicating between different (client and server) applications and devices. Now, because of their crucial role, the presence of malicious software in them can be catastrophic to your web app.

To prevent this, the NGINX App Protect uses the XML, JSON, and gRPC content profile to detect and remove malicious content and signatures in their respective element values. It also enforces size restrictions and prohibits access to unknown fields, although it does allow you to customize the maximum size and structure depths.

Pros and Cons of NGINX App Protect



It is flexible and can be integrated into all DevOps environments.

It takes time to be deployed and has a complex setup procedure.

It acts as an effective reverse proxy.

Its policies are created and handled manually, and this process takes time.

It is not expensive and offers a free 30-day trial.

It doesn’t increase web latency.

ModSecurity Web Application Firewall

The ModSecurity WAF is an open-source web application security solution that uses core and commercial rules to protect your web apps from malicious attacks. It monitors web traffic requests and prevents unauthorized access to your web applications by checking all income requests against the security rules you set in the WAF.

In addition, It works as a web server module for different web servers like NGINX, Microsoft IIS, and Apache. It was initially built to be Apache-independent, but since the release of its 3.0 version, it now has a central library that can easily connect it to different servers – including a dynamic support module that allows you to customize a third-party module of your choice.

Here are two of its basic features.

Two Main Features of ModSecurity Web Application Firewall

  • Core and customized rulesets

Like most traditional web application firewalls, ModSecurity uses a set of complex and simple rules to secure your web apps against malicious traffic flexibly. Its core rulesets are free, used in the open-source environment, and effectively protect web applications from OWASP Top 10 attacks, SQL injections, Cross Site Scripting, DoS, and other known web attacks. On the other hand, ModSec uses paid commercial rules to protect your web applications from unknown web attacks and zero days.

  • Persistent storage

Unlike other WAFs, ModSecurity offers a standalone feature dedicated to ensuring the integrity of your data. This data persistence feature ensures that your sensitive data is always kept safe, even after a web attack or if the app is shut down. It allows you to retrieve your data and keep track of user behavior over an extended period.

Pros and Cons of the ModSecurity Web Application Firewall



Its product support team quickly replies and effectively solves any problems you encounter while using the WAF.

A beginner might find using it difficult to understand.

It can be deployed on different web servers.

It’s difficult to isolate and rewrite rules that cause false positives.

It is an open-source web application firewall.

It is easy to install.

open-appsec Web Application Firewall Review.

Are you looking for a way to block web attacks on your web apps before they happen? open-appsec uses two machine learning algorithms to continuously detect and preemptively block threats before they can do any damage. Our code has also been published on GitHub, and the effectiveness of our WAF has been successfully proven in numerous tests by third parties. Try open-appsec in the Playground today.

The open-appsec web application firewall is an open-source solution that uses a machine-learning approach to guard your web application against attacks. It uses this machine-learning WAF approach to study your app’s unique structure and develop trends and insights that help it mitigate web attacks.

It doesn't use signatures, rules, policies, or exceptions, so it doesn't require system updates and has very few cases of false positives.

Due to its unique approach to fighting against web attacks, this newly developed WAF could preemptively detect and prevent the access of zero-day attacks like the Log4shell, Spring4Shell, Text4Shell, and even a JSON-infused SQL Syntax modality created by the Claroty Team82 to test the ability of popular WAFs.

Try open-appsec in the Playground today.

Below are some of its core features.

Features of open-appsec Web Application Firewall

  • Machine-learning-based application firewall

Popular web application firewalls compare incoming requests against a set of managed and customized rulesets as an approach to detect malicious traffic. But the open-appsec WAF uses two machine learning models to keep your web application safe.

These two machine-learning models are:

  1. An offline model trained with data from millions of (both malicious and benign) requests worldwide – best used in test environments.

  2. A more advanced and accurate online machine learning model that monitors real-time requests and develops insights to mitigate malicious attacks.

Note that the presence of rules, signatures, exceptions, and policies, as seen in other popular WAFs, effectively protects web apps from known vulnerabilities and attacks but does not do a good job of protecting against unknown attacks. This is where the open-appsec WAF's machine learning approach takes the leading role.

  • Anti-bot

The open-appsec WAF is one of the few web application firewalls with a dedicated bot prevention feature. This feature automatically identifies and stops brute force attacks before they cause harm to your web applications. It does this for normal and malicious bots that scrape and scan web applications for vulnerabilities.

Note that the open-appsec WAF also uses machine learning (not rules and signatures) to prevent bot attacks. This is because its constantly improving self-learning approach is more effective against ever-adaptive and evasive bot attacks.

  • API security

API calls make up more than 50% of web traffic. Because of these numbers, cybercriminals are notoriously known to inject malware into an application’s structure through API calls.

To prevent this, the open-appsec WAF has an API security feature that monitors all your API endpoints using machine learning and Open API Schema (for its premium version) to prevent the injection of malicious software. It also hardens your application’s attack surface to keep your application’s activities within safe limits. Not only this, it provides real-time insights to keep you readily informed of your API’s activities and efficiencies.

Pros and Cons of open-appsec Web Application Firewall



It is an open-source solution.

It has a small community.

It discovers very few false positives.

It is a new WAF.

It does not increase web latency.

t uses a declarative system configuration to declare actions and results.


The choice between NGINX App Protect, ModSecurity WAF, and open-appsec WAF ultimately depends on your organization's specific needs and goals.

NGINX App Protect offers a commercial solution that uses policies to achieve advanced web application security features. ModSecurity WAF is an open-source solution with a large community of users and a wealth of knowledge and resources. In comparison, open-appsec WAF is also an open-source solution that uses machine learning to preemptively defend your web application against known and unknown web attacks. Try open-appsec in the Playground today.

Regardless of the WAF solution you choose, it is important to remember that WAFs are just one aspect of a comprehensive security strategy. It is also important to consider other security measures such as user education and training and implementing secure coding practices. By taking a holistic approach to security, you can ensure that your web applications are protected against a wide range of cyber threats.


The difference between NGINX App Protect and NGINX Plus.

NGINX Plus is a premium version of the popular open-source web server software NGINX. It offers enhanced performance, additional features, and enterprise-level support compared to the basic version.

On the other hand, NGINX App Protect is a standalone security solution offered by NGINX, Inc. that protects against various application-layer threats such as SQL injection, cross-site scripting (XSS), and malicious file uploads.

What is the difference between NGINX ModSecurity and App Protect?

NGINX ModSecurity is a module for the NGINX web server that integrates with the ModSecurity Web Application Firewall (WAF), an open-source WAF that protects against various web application security threats.

NGINX App Protect, on the other hand, is a security solution offered by NGINX, Inc. that protects against the same types of threats as ModSecurity but with additional features and benefits.

Can NGINX app Protect be called a WAF?

NGINX App Protect can be referred to as a Web Application Firewall (WAF). This is because, like a WAF, it protects web applications from attacks by inspecting incoming traffic and blocking malicious requests. Using machine learning and rules-based methods, it also protects against common web application attacks, including zero-day vulnerabilities.

What is the difference between WAF and proxy?

A WAF is a specialized security solution specifically designed for protecting web applications, while a proxy can serve multiple purposes, including security. However, a WAF provides more specific and advanced security features when compared to a generic proxy server.

Is WAF better than a firewall?

Whether a Web Application Firewall (WAF) is better than a firewall depends on an organization's specific use case and security requirements. This is because firewalls and WAFs have unique pros and cons and can complement each other in providing comprehensive security for your organization. A firewall is suitable for network-level security, while a WAF is best suited for protecting web applications. An organization's specific security needs will determine whether a firewall, WAF, or a combination of both is the best solution.


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