Best Web Application Firewalls (WAF) for Linux of 2025

SKUDONET provides IT leaders with a cost effective platform that focuses on simplicity and flexibility. It ensures high performance of IT services and security. Effortlessly enhance the security and continuity of your applications with an open-source ADC that enables you to reduce costs and achieve maximum flexibility in your IT infrastructure.

CacheGuard product line is based on a core product called CacheGuard-OS. Once installed on a bare metal or virtual machine, CacheGuard-OS transforms that machine into a powerful network appliance . The resulted appliance can then be implemented as different types of Gateways to Secure & Optimize your network. See below a brief description of all CacheGuard appliances. - Web Gateway: gain control over the Web traffic in your organization & filter unwanted Web traffic in your organization. - UTM (Unified Threat Management) : secure your networks against all kind of threats coming from the internet with a Firewall, an Antivirus at the Gateway, a VPN server and a Filtering proxy. - WAF (Web Application Firewall): block malicious requests on your critical Web applications and protect your business. The WAF integrates OWASP rules with the possibility to design your own custom rules. In addition, an IP reputation based filtering allows you to block IPs listed in real time blacklists. - WAN Optimizer : prioritize your critical network traffic, save your precious bandwidth and get High Availability for your internet access through multiple ISP.

Haltdos ensures the 100% high availability of your website/web services by providing intelligent Web Application Firewall and application DDoS mitigation, Bot Protection, SSL offloading, Load Balancing solution over the public and private cloud that monitors, detects, and automatically mitigates a wide range of cyber-attacks including OWASP top 10 and Zero-day attacks, without requiring any human intervention.

Fortinet stands out as a prominent global entity in the realm of cybersecurity, recognized for its all-encompassing and cohesive strategy aimed at protecting digital infrastructures, devices, and applications. Established in the year 2000, the company offers an extensive array of products and services, which encompass firewalls, endpoint security, intrusion prevention systems, and secure access solutions. Central to its offerings is the Fortinet Security Fabric, a holistic platform that effectively melds various security tools to provide enhanced visibility, automation, and real-time intelligence regarding threats across the entire network. With a reputation for reliability among businesses, governmental bodies, and service providers across the globe, Fortinet places a strong emphasis on innovation, scalability, and performance, thereby ensuring a resilient defense against the ever-evolving landscape of cyber threats. Moreover, Fortinet’s commitment to facilitating digital transformation and maintaining business continuity further underscores its role as a pivotal player in the cybersecurity industry.

Our engineers are specialists at working in sectors where zero downtime is critical. Since 2003, we’ve been building a reputation for delivering ultra-reliable, easy to deploy and effortlessly scalable applications that are trusted by solution partners, system integrators and end-users alike. Our focus on forming long-lasting partnerships with industry-leading solution providers in healthcare, storage and print, requires an in-depth understanding of both our partners and their clients’ technical and business practices. The result: unprecedented levels of uptime.

We offer the most user-friendly technology without sacrificing performance or features. We back it up with exceptional support and care delivered under a fair, cost-effective pricing model Our technology is used by small startups with big ideas, small budgets, and global enterprises. We love them all! Easy to use Load balancing, WAF, GSLB and SSO/Pre-Authentication. It is also the only true ADP Application Delivery Platform that allows for the enhancement of functionality and longevity using the app store or apps you create in-house.

open-appsec is an open-source initiative that builds on machine learning to provide pre-emptive web app & API threat protection against OWASP-Top-10 and zero-day attacks. It can be deployed as add-on to Kubernetes Ingress, NGINX, Envoy and API Gateways. The open-appsec engine learns how users normally interact with your web application. It then uses this information to automatically detect requests that fall outside of normal operations, and sends those requests for further analysis to decide whether the request is malicious or not. open-appsec uses two machine learning models: 1. A supervised model that was trained offline based on millions of requests, both malicious and benign. 2. An unsupervised model that is being built in real time in the protected environment. This model uses traffic patterns specific to the environment. open-oppsec simplifies maintenance as there is no threat signature upkeep and exception handling, like common in many WAF solutions.

Managing application delivery at scale can be challenging, but NetScaler simplifies the process. Whether you are firmly on-premises, fully in the cloud, or operating in a hybrid environment, NetScaler provides consistent functionality across all platforms. Its architecture is built on a single code base, ensuring that regardless of whether you opt for hardware, virtual machines, bare metal, or containers, the performance remains uniform. No matter if your audience consists of hundreds of millions of consumers or hundreds of thousands of employees, NetScaler guarantees reliable and secure application delivery. Renowned as the preferred application delivery and security solution for the largest enterprises globally, NetScaler is trusted by thousands of organizations, including over 90 percent of the Fortune 500, to deliver high-performance application services, robust application and API security, and comprehensive visibility across all operations. This widespread trust underscores NetScaler's vital role in today's digital landscape.

BunkerWeb represents a cutting-edge, open-source Web Application Firewall (WAF) designed for modern web security needs. As a fully functional web server built on NGINX, it ensures that your web services are inherently "secure by default." This tool integrates effortlessly into various environments, including Linux, Docker, Swarm, and Kubernetes, and offers complete configurability through an intuitive web interface for those who prefer it over command-line options. In essence, it simplifies the complexities of cybersecurity, making it accessible for all users. Additionally, BunkerWeb includes essential security features in its core system, while also allowing for easy enhancement through a flexible plugin architecture, ensuring that it can adapt to a wide range of security requirements.