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What You Need to Know About AWS WAF, AWS Shield Advanced, and open-appsec WAF

To help you make a wise web application firewall (WAF) choice, this article discusses the features, pros, and cons of three popular application security services: AWS WAF, AWS Shield Advanced, and open-appsec WAF.

Let’s get started.

Comparing AWS Shield Advanced, AWS WAF, and open-appsec WAF


AWS Shield Advanced


open-appsec WAF

ML-based WAF. No signatures needed



It uses machine learning algorithms to ensure the security of your web apps and preemptive zero-day protection.

DDoS prevention




WAF community and customer service

It has a large community.

It has a large community of users.

The open-appsec community is small, so when you reach out for help, you won't have to wait long for an administrator to answer and provide assistance with any problems you may experience while utilizing the platform.


It is not open-source.

It is not open-source.

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

False positives




Maintenance complexity

Simple. Managed service.

Significant tuning is needed to deal with false postives.

Provides easy system maintenance as it doesn't use threat signatures, rules, and exception handling to protect your web app against attacks.

Free version

There's a yearly subscription plan of $3,000 plus additional fees for extra resources you use.

Its pricing is based on the number of rules you use and the number of incoming and outgoing traffic it monitor’s for your app.

It is free and also has a paid premium version.

Declarative Configuration




Intrusion prevention system used


Not Available.

Uses Snort 3.0 engine.

Similarities: AWS Shield Advanced, AWS WAF, open-appsec WAF.

1. These solutions are designed to protect web applications from security threats.

2. All three solutions work by inspecting incoming HTTP traffic to identify and block malicious requests before they reach your target web application.

3. All three solutions can be integrated with other security tools and services.

4. All three solutions are designed to be flexible and can be configured to meet the specific security requirements of your web application.

Review: AWS Shield Advanced

AWS Shield Advanced is an application security service that protects AWS-hosted web applications against DDoS attacks, volumetric bots, and vulnerability exploitation attempts. It is situated at layers 3, 4, and 7 of your app’s architecture and provides suitable, flexible, and sophisticated protection.

Unlike its counterpart, AWS Shield Standard, it provides advanced protection for web apps running on Amazon Elastic Compute Cloud, Amazon Elastic Load Balancer, Amazon CloudFront, AWS Global Accelerator, Amazon Route 53, etc.

While AWS Shield Advanced ensures that your web app is not susceptible to DDoS attacks, it is not a web application firewall. So it can not effectively protect your app against other common web attacks like the SQLi, XSS, OWASP top 10 attacks, etc.

Here are two of its most outstanding features.

Features of AWS Shield Advanced

  • AWS Shield Standard

Once you subscribe to AWS Shield Advanced, you automatically get access to all AWS WAF's basic features. Therefore, AWS Shield Advanced automatically deploys your web Access Control List (ACL), rules, and rule group configurations in the WAF to protect your application against DDoS attacks.

  • Enhance DDoS attack visibility

While AWS Shield Standard also provides bi-weekly and yearly insights into the DDoS attacks against your web apps, Shield Advanced takes this data report sheet further. It gives additional data on individual attacks, allows you to configure these insights on CloudWatch dashboards, and grants you cross-environment access to these insights if you're using AWS Firewall Manager.

Pros and Cons of AWS Shield Advanced



It offers strong protection against DDoS attacks.

It is expensive.

It is easy to set up and has an easy user interface.

It doesn’t protect your web application against other attacks.

Its integration with other Amazon Web Services makes it easy to host, secure, and monitor the activities going on in your web application.

AWS Web Application Firewall Review

The AWS Web Application Firewall is a cloud-based and on-premises web application firewall that protects your application from web attacks. It does this by monitoring all incoming traffic and checking them against a combination of configured rules to differentiate malicious traffic from legitimate requests.

After it detects a request's intent, it either grants it access to your web application, blocks it, or shows it a customized message (to help reduce the chances of false positives). One of the most rudimentary features of the AWS WAF is its core rules. With this feature, you can create streamlined security that prevents requests with specific IP addresses, countries, string matches, etc., from accessing your web application.

Below are some of its core features.

Features of the AWS Web Application Firewall.

  • Real-time visibility

Because it can be integrated with Amazon CloudWatch metrics, it captures the data of all incoming and outgoing requests, events, and attacks and shows you a real-time report. This report gives you insight into your application's security activity. It will also suggest the best way to tweak your current rules to secure your app better.

  • Bot control

Because of the harmfulness and evasiveness of emerging bots, the AWS WAF has a dedicated rule group called AWS Bot Control. This rule group contains a list of rules built around known bot characteristics. The group is divided into managed (predefined by the AWS security team) and customized rules, which also give you insight into bot characteristics and activity to help improve your app's security.

Pros and Cons of the AWS WAF



It doesn’t increase web latency.

It is only for AWS-hosted applications.

It is effective against pervasive bot attacks.

No zero-day pre-emptive protection

It can be deployed in the cloud and on-premises.

Signifcant manual tuning is needed to deal with false positives.

It offers tailored web application security because of its customized rules.

open-appsec WAF review

Are you looking for a way to block attacks on your web application before they happen? open-appsec uses machine learning 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.

open-appsec WAF is an open-source web application firewall that utilizes machine learning to provide robust protection against OWASP Top 10 and zero-day attacks such as Log4Shell, Text4Shell, and Spring4Shell. It integrates seamlessly with popular technologies such as NGINX, Kubernetes, and Envoy; it is easy to set up and manage with a cloud-native deployment process that leverages declarative APIs and infrastructure-as-code.

Most web application firewalls use signatures to protect your web application against known and unknown vulnerabilities. While these signatures effectively protect your app from known attacks, they poorly guard against unknown vulnerabilities in advance. One way that WAFs can do this is by broadening the scope of their signature; however, this would increase the case of false positives, which is common with WAFs. To prevent cases like this, the open-appsec WAF uses two machine learning models to protect your web application against known and unknown attacks.

Its first ML (machine learning) algorithm is offline and supervised. It checks incoming requests against malicious threat indicators and assigns threat scores according to confidentiality level. This offline model is supervised and contains data from millions of malicious and benign requests worldwide. If a request is deemed legitimate, it is allowed access to your web application. On the other hand, if it's flagged as malicious, it is pushed to the WAF's second ML algorithm.

The second ML algorithm is online and unsupervised. It analyzes the malicious request against your app's structure and user behavior based on criteria such as the user's reputation score, the payload score, the URL score, and the parameter score. Following its evaluation, it blocks the requests or permits them to access your web application. The main purpose of this unsupervised online ML algorithm is to reduce the chances of false positives.

The open-appsec WAF generally offers a holistic approach to web application security. It proactively protects your apps against known and unknown exploits, hardens your API attack surface, offers an exclusive bot prevention service, and ensures smooth content delivery while making sure not to increase web latency.

Try open-appsec in the Playground today.

Below are some other features of the open-appsec WAF.

Features of open-appsec

1. Provides ML Threat Prevention.

2. Provides API Security.

3. Intrusion Prevention.

4. Integration with Kubernetes, NGINX, NGINX Ingress, etc.

5. Real-time data logs and analytics.

Pros and Cons of open-appsec WAF



It uses a declarative system configuration to declare actions and outcomes.

It is a fairly new WAF.

It offers preemptive protection against attacks.

It has a small community.

It effectively protects web applications against unknown attacks.

It is open-source.

It has a free version.

It has multiple integrations.

There's simple system maintenance due to the absence of threat signatures, rules, and exception handling.


While these three web application firewalls each have unique features, here's how to best use them.

AWS Shield Advanced is the best choice for web applications whose major security threat are DDoS attacks. AWS WAF is the best web application firewall to protect your AWS-hosted app from attacks. And open-appsec is the best choice if you want a holistic and waterproof web application firewall to keep your app safe from known and unknown attacks. Try open-appsec in the Playground today.

Frequently Asked Questions

What is the difference between AWS network firewall and AWS WAF?

AWS Network Firewall is a managed firewall service that protects network traffic by monitoring and controlling inbound and outbound traffic based on the rules you define. On the other hand, AWS WAF is a WAF that protects your web apps from common exploits. The services are complementary and can be used together to provide comprehensive protection for your resources in the AWS Cloud.

Which statement best contrasts AWS Shield and AWS WAF?

AWS Shield is a managed service that automatically protects against DDoS attacks for all AWS customers. In contrast, AWS WAF provides more specific protection for web applications and allows customers to define custom rules for controlling incoming traffic.

What is the difference between AWS Shield Standard and AWS Shield Advanced?

AWS Shield is an application security service dedicated to protecting web applications against Distributed Denial of Service (DDoS) attacks. It is divided into AWS Shield Standard and AWS Shield Advanced. They both provide protection against DDoS attacks, but AWS shield is free and offers basic features, while Shield Advanced is paid and offers more sophisticated DDoS protection.

What is the difference between AWS Web Application Firewall and ACL?

AWS WAF is an app security service that provides fine-grained control over HTTP and HTTPS traffic to web applications, allowing customers to protect their web applications from common exploits such as SQL injection, cross-site scripting, and others. In comparison, ACL is a set of rules that allow or deny traffic to and from the associated resource. AWS WAF offers web ACL as one of its main features, which guides the WAF to protect your web app when configured.

Experiment with open-appsec for Linux, Kubernetes or Kong using a free virtual lab

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