List of the Top 9 Web Application Firewalls (WAF) for Linux in 2025

SKUDONET offers IT executives an affordable solution that emphasizes ease of use and adaptability, ensuring optimal performance and security for IT services. With this innovative platform, you can seamlessly improve the security and reliability of your applications through an open-source ADC, allowing for significant cost savings and unparalleled flexibility within your IT framework. This approach not only streamlines operations but also empowers organizations to respond swiftly to changing technology needs.

The CacheGuard product range revolves around a foundational offering known as CacheGuard-OS. When installed on either a physical or virtual machine, CacheGuard-OS effectively converts that system into a robust network appliance. This newly formed appliance can serve multiple functions as various types of gateways that enhance the security and efficiency of your network. Below is a concise overview of the various CacheGuard appliances available. - Web Gateway: exercise control over organizational web traffic and filter out undesirable web access. - UTM (Unified Threat Management): protect your networks from a wide array of online threats using a combination of a firewall, antivirus at the gateway, VPN server, and a filtering proxy. - WAF (Web Application Firewall): prevent harmful requests from reaching your essential web applications and safeguard your enterprise. The WAF incorporates OWASP rules while allowing for the creation of custom rules, along with an IP reputation filtering system that enables the blocking of IPs identified in real-time blacklists. - WAN Optimizer: optimize the flow of your vital network traffic, conserve bandwidth, and ensure high availability for your internet connection through the use of multiple ISPs. Each appliance is designed to address specific network challenges, ultimately providing comprehensive solutions tailored to your organization’s needs.

Haltdos guarantees complete high availability for your website and web services through its advanced Web Application Firewall, application DDoS mitigation, Bot Protection, SSL offloading, and Load Balancing solutions, all deployed across both public and private cloud environments. It continuously monitors, identifies, and autonomously addresses a variety of cyber threats, including the OWASP top 10 vulnerabilities and Zero-day attacks, effectively eliminating the need for human involvement in the mitigation process. This proactive approach not only enhances security but also ensures that your online operations remain seamless and uninterrupted.

Fortinet emerges as a key global player in the cybersecurity sector, notable for its comprehensive and integrated approach to safeguarding digital infrastructures, devices, and applications. Founded in 2000, the organization provides a wide range of products and services, including firewalls, endpoint protection, intrusion prevention systems, and secure access solutions. A cornerstone of its offerings is the Fortinet Security Fabric, a unified platform that seamlessly combines various security tools to enhance visibility, automation, and provide real-time threat intelligence across the entire network. Renowned for its dependability among businesses, government agencies, and service providers worldwide, Fortinet prioritizes innovation, scalability, and performance, thereby reinforcing its defenses against the constantly shifting landscape of cyber threats. In addition to its protective capabilities, Fortinet’s dedication to enabling digital transformation and ensuring business continuity highlights its essential role within the cybersecurity landscape, positioning itself as a trusted partner for organizations striving to navigate modern security challenges effectively. With a focus on proactive measures and cutting-edge solutions, Fortinet continues to adapt and evolve to meet the demands of an increasingly complex digital world.

Our engineering team excels in industries where uninterrupted service is essential. Since the year 2003, we have established a strong reputation for providing highly reliable applications that are not only simple to implement but also easily scalable, earning the trust of solution partners, system integrators, and end-users. By prioritizing the development of enduring relationships with top-tier solution providers in fields such as healthcare, storage, and printing, we are able to gain a comprehensive insight into the technical and business needs of both our partners and their clients. This commitment leads to unmatched levels of operational continuity and customer satisfaction, ensuring that businesses can thrive without interruptions.

Our technology is designed to be incredibly user-friendly while still maintaining high performance and a full range of features. We complement this with outstanding support and a commitment to fair, affordable pricing. Our solutions cater to everyone, from ambitious small startups with limited resources to large global corporations, and we appreciate each one of them! With straightforward options like Load balancing, WAF, GSLB, and SSO/Pre-Authentication, you can easily integrate our offerings. Moreover, we proudly present the only genuine ADP Application Delivery Platform that enables you to enhance both functionality and longevity through our app store or applications developed internally. This versatility ensures that all users can tailor the technology to meet their specific needs effectively.

Open-appsec is an innovative open-source project that leverages machine learning to deliver proactive security measures for web applications and APIs, safeguarding against the OWASP Top 10 vulnerabilities as well as zero-day exploits. This system can be seamlessly integrated as an add-on to Kubernetes Ingress, NGINX, Envoy, and various API Gateways. The core engine of open-appsec observes typical user interactions with your web application, utilizing this behavior data to identify any requests that deviate from established norms, subsequently forwarding these anomalies for further scrutiny to determine their potential maliciousness. To achieve this, open-appsec employs two distinct machine learning models: 1. A supervised model developed offline, drawing insights from millions of both malicious and harmless requests. 2. An unsupervised model that evolves in real time within the protected environment, focusing on the unique traffic patterns of that specific setting. In addition to its robust detection capabilities, open-appsec streamlines maintenance by eliminating the need for frequent threat signature updates and exception management, which are often prerequisites in many conventional WAF solutions. Overall, open-appsec not only enhances security but also reduces the complexity typically associated with managing web application firewalls.

Managing application delivery at scale presents various challenges, yet NetScaler streamlines this task effectively. Whether your operations are entirely on-premises, completely cloud-based, or situated in a hybrid model, NetScaler ensures seamless functionality across all environments. Built on a unified code base, its architecture guarantees that performance remains consistent, whether utilizing hardware, virtual machines, bare metal, or containers. Regardless of whether your user base includes hundreds of millions of customers or just hundreds of thousands of employees, NetScaler promises dependable and secure application delivery. Recognized as the leading application delivery and security solution among the world's largest enterprises, NetScaler is relied upon by thousands of organizations, with over 90 percent of the Fortune 500 counting on it to provide high-performance application services, strong application and API security, and exhaustive visibility into all operations. This extensive reliance highlights NetScaler's crucial importance in the contemporary digital landscape, emphasizing its role in not just meeting but exceeding user expectations.

BunkerWeb stands out as an innovative, open-source Web Application Firewall (WAF) tailored for the security requirements of contemporary web applications. Functioning as a full-fledged web server based on NGINX, it guarantees that your web services are "secure by default." This tool can be seamlessly integrated into diverse environments such as Linux, Docker, Swarm, and Kubernetes, and provides complete configurability via a user-friendly web interface for those who favor it over command-line interactions. In essence, BunkerWeb streamlines the intricacies of cybersecurity, making it user-friendly for everyone, regardless of their technical background. Moreover, BunkerWeb is equipped with vital security features within its core framework while also facilitating easy upgrades through a versatile plugin system, ensuring it can meet a wide array of security needs. With its adaptable architecture, users can tailor their security solutions to fit specific operational contexts, enhancing overall web protection.