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Discovering WAF: open-appsec vs. Incapsula vs. Azure WAF

When protecting websites and web applications from various security threats, choosing the right web application firewall (WAF) solution is critical.

This article will compare three popular WAF solutions: Incapsula, Azure, and open-appsec, to help you understand their key differences and determine which one might best meet your needs. Also, it will introduce you to how the open-appsec WAF uses a machine learning-based security solution to protect your application from web attacks.

Web App Firewall Cyber Solution Comparison Table


Azure WAF




ML-based. No signature needed




Zero-day protection




API protection




Protection against OWASP TOP 10 attacks







Yes (premium feature)


Declarative configuration and deployment




SaaS Web-based Event Management & Dashboards

Yes, Azure Log analytics

Yes, Security events page







Free version



Yes, for unlimited HTTP requests


Policy for $5 per month Custom rules for $1 per month and requests processed for $0.6 per million requests Default ruleset for $20 per month and requests processed for $1 per million requests

Pro model for $59 per month

Business model for $299 per month

Enterprise model at a custom quotation, depending on your needs

Premium edition, pay-as-you-go per 1M HTTP requests

Enterprise edition,

Annual payment per 100M HTTP requests

Incapsula (Imperva) Web Application Firewall

The Imperva Web Application Firewall (WAF) is a network security solution that protects web applications from cyber attacks. It monitors incoming and outgoing traffic to and from a web application and blocks malicious requests.

The WAF uses a combination of rulesets and signature-based detection to identify and prevent attacks such as SQL injection, cross-site scripting (XSS), and other web application vulnerabilities. It also provides security features such as IP reputation analysis, rate limiting, bot management etc. The WAF operates at the network layer, providing an additional layer of security to web applications and helping to ensure their availability and integrity.

Below are some of its features

Features of Incapsula (Imperva) WAF

● Virtual Patch Management Module

Since most security issues are caused by human error, the developers of the Incapsula WAF added a virtual patch management module to roll out and release ALL software and OS patches to prevent a breach caused by negligence or other human factors. In collaboration with Hight-Tech Bridge, Imperva created a highly reliable patch module streamlined by rulesets to help protect your web apps against DDoS attacks and other web attacks.

This module not only sieves known vulnerabilities in incoming requests but also updates you on new rules and signatures that will keep your app safe from zero-day attacks.

● Runtime Application Self-Protection (RASP)

Incapsula's most peculiar feature is this security software module that monitors unknown payloads and insider or partner threats in real-time. This feature generally protects your web app against attacks (like clickjacking and path traversal), injections (like SQL injection and Cross Site Scripting), weak cryptography and authentication, etc.

This feature gets seamlessly and autonomously deployed into your app environment, where it works in the background to secure your data's integrity, confidentiality and availability.

● Policy management

This feature allows enterprise customers to manage the security of multiple sites from a central location. With this feature, you can block incoming requests from specific countries, specific URLs, and IDs and set exceptions and actions to take if a request violates the set rules. This feature also allows you to automatically set these rules or policy parameters to one or more sites.

Pros and Cons of Incapsula (Imperva) WAF



Intelligent, real-time traffic profiling.

You need to provide your private keys to Imperva

Protection against sophisticated bots, SQL injection, intruders, etc.

No pre-emptive zero-day protection as it uses signatures

Protects against direct-to-IP DDOS attacks, application layer, and network layer attacks like SYN floods or GET floods.

Will not protect access within your data center, only from the Internet

Microsoft Azure WAF

When your objective is to protect your web applications from common techniques like cross-site scripting and SQL injection, Azure web application firewall could be your solution. This cloud-native service is easy to deploy and will give you complete visibility into your environment. You have control over its managed rulesets which can be customized to protect against malicious attacks.

If your organization deals with highly critical data (PII and SPII), you may deploy Azure WAF to protect against intrusion and data exfiltration. It can also detect exploits such as local file inclusion attempting account takeover by stealing/ displaying credentials. It further allows input sanitization. That is, it approaches user-supplied inputs in the zero trust style by insulating your web applications from them, thus preventing harm from malicious scripts.

Azure WAF can be managed through its integration with security tools like Microsoft Defender for Cloud, and you can create your firewall rules directly from the Defender portal. Similarly, it can be integrated with Microsoft’s SIEM tools, thus making identifying new threats easier.

The latest version of Azure WAF is configured with CRS 3.2, has new rule sets protecting against Java injections, initial checks for file uploads, and fewer false positives compared to older versions.

Pros and Cons of Microsoft Azure WAF



Deployment options are available using Azure Application Gateway, Azure CDN, and Azure Front door.

Very basic bot mitigation, with no fingerprinting and JS provision, challenges distinguishing between good and bad bots.

Azure WAF allows you to set certain attributes to be ignored during request validation.

Does not have advanced API security measures (specifically, it can’t automatically detect and categorize APIs like other WAAP vendors).

You can have requests flagged if they exceed certain size limits.

No pre-emptive zero-day protection as it uses signatures

Microsoft’s managed WAF rules are automatically updated to block threats.

Challenging integration with third-party SIEM tools.

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 andpreemptively block threats before they can do any damage. Ourcode has also been published on GitHub, and the effectiveness of our WAF has been successfully proven in numeroustests by third parties. Try open-appsec in thePlayground today.

open-appsec incorporates a machine learning-based approach toward web application and API security through continuous monitoring and analysis of HTTP(S) requests. Moreover, this open-source security solution's intelligent threat protection safeguards your web applications against OWASP 10 and zero-day attacks. open-appsec's analysis functions consider your web application structure and user interaction to identify patterns, thus automatically filtering out and blocking malicious threat actors.

The following summarizes some key features of open-appsec:

● The open-appsec web application firewall is a machine learning based, ensuring no false positives and minimal need for tuning.

● Behavioural anti-bot is available to stop automated attacks before the intrusion.

● Intrusion Prevention System protection is available against 2800+ web CVEs based on Check Point award-winning NSS-certified IPS.

● The IPS has Snort 3.0 support, thus making it capable of capturing and analyzing real-time web traffic.

● It allows integration into modern environments and workloads for the public cloud and Kubernetes and CI/CD workflows supporting Kubernetes Ingress, Docker, and Linux servers.

● An HTTPS traffic monitoring storage facility is available for your SSL certificates and private keys locally or in the public cloud (AWS/ Azure).

● Easy management and maintenance of Enterprise-grade SaaS Web UI, GraphQL API, and Infrastructure-as-code using Terraform.

Many users of other web applications and API security tools frequently complain about not having proper, easy-to-use event monitoring and logging systems. But open-appsec has solved this issue by allowing automatically created and editable audit logs to be viewed under its Monitoring section.

Meanwhile, open-appsec provides two security best practices that could be activated easily in detect/ learn mode or prevent mode. They utilize many security engines to analyze HTTP web requests to present accurate results on whether a request is malicious or benign. These engines protect your web applications and APIs against well-known and new, sophisticated web attack techniques and CVEs, differentiating between requests from humans and bots and validating API inputs.

Additionally, you can seamlessly manage open-appsec in the DevOps style with its SaaS web-based event management and dashboards. Moreover, open-appsec’s support is available for all its editions, making your management easier as your issues get addressed. For enterprise users, you can request an advisor to guide you through integrations with third-party SIEM and API integrations.

Pros and Cons of open-appsec WAF



ML-based WAF for attack mitigation

It is a new security solution

Behavioral-based anti-bot

Small community of users

Automatic IPS security updates for Premium and Enterprise editions users

Not a lot of information is available on the internet

Snort 3.0 Support available for IPS engine

ThreatCloud to block malicious IPs, anonymizers, and Tor for Enterprise users

Log Storage in the Cloud facility is available for all users (10K events per month for community users, 1M events per month for Premium users, and 100M events per month for Enterprise users)

Automatic upgrades (Premium and Enterprise editions)

Support available for all users

Enterprise users can request an integration advisor


Azure WAF is an affordable web protection solution to secure your website against common techniques like SQL injection or XSS. But, if you have the budget and your organization needs comprehensive security (including protection against DDOS attacks and faster loading websites), Incapsula may be a better solution.

Not sure about your security needs and allocated budget for that? Then you could go for the open-source security alternative open-appsec, which has a machine learning-based approach towards security and assures protection against OWASP 10, zero-day, and botnet. Try open-appsec in the Playground today.

Frequently Asked Questions

How does Incapsula work?

It uses DNS redirection. This way, web traffic is routed through the Incapsula network, ensuring that only legitimate traffic is allowed in and malicious traffic is blocked.

Can Incapsula be used in Azure?

Yes, the Incapsula network filters out malicious web traffic before it reaches Azure. It does so using advanced bot protection and client classification.

Bình luận

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

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