Open Source C Web Application Firewalls (WAF)

CacheGuard Gateway is a free and open-source Unified Threat Management (UTM) solution, a Web Application Firewall (WAF), and a Quality of Service (QoS) platform designed to optimize WAN traffic. To obtain a CacheGuard Gateway appliance, download CacheGuard-OS and install it on the bare-metal or virtual machine of your choice. It’s that simple and completely free. The UTM includes a firewall, web antivirus, VPN server, and a URL-filtering and SSL-inspection web proxy. The WAF operates in conjunction with a reverse proxy, web application load balancer, and SSL offloader, and is capable of blocking malicious requests as well as traffic from IP addresses with poor reputations. The QoS manager enables traffic shaping to prioritize critical network flows, load balance multiple WAN links, and cache web traffic.

Handy, High-performance Nginx firewall module. Such as black and white list of IPs or IP range, uri black and white list, and request body black list, etc. Directives and rules are easy to write and readable. The IP detection is a constant-time operation. Most of the remaining inspections use caching to improve performance. Compatible with ModSecurity's rules, you can use OWASP ModSecurity Core Rule Set. Supports verifying Google, Bing, Baidu and Yandex crawlers and allowing them automatically to avoid false positives. Supports three kinds of captchas: hCaptcha, reCAPTCHAv2 and reCAPTCHAv3.

Tempesta FW is an all-in-one open-source solution for high performance web content delivery and advanced protection against DDoS and web attacks. This is a drop-in-replacement for the whole web server frontend infrastructure: an HTTPS load balancer, a web accelerator, a DDoS mitigation system, and a web application firewall (WAF). Tempesta FW is the first and only hybrid of a Web accelerator and a multi-layer firewall. This unique architecture provides seamless integration with the Linux iptables or nftables. Tempesta FW services up to 1.8M HTTP requests per second on the cheapest hardware, which is x3 faster than Nginx or HAProxy. Tempesta TLS is about 40-80% faster than Nginx/OpenSSL and provides up to x4 lower latency.

The first all-round open source Web security protection system, more protection than others. OpenWAF is the first fully open source Web application protection system (WAF), based on nginx_lua API analysis of HTTP request information. OpenWAF is composed of two functional engines: behavior analysis engine and rule engine. The rule engine mainly analyzes the individual requests, and the behavior analysis engine is mainly responsible for the tracking of the request information. Rule engine inspired by modsecurity and freewaf(lua-resty-waf), the ModSecurity rules will be implemented using lua. The rule engine can be based on the protocol specification, automatic tools, injection attacks, cross site attacks, information leaks and other security exception request, adding support for dynamic rules, timely repair vulnerabilities.

ModSecurity is a web application firewall that can work either embedded or as a reverse proxy. It provides protection from a range of attacks against web applications and allows for HTTP traffic monitoring, logging and real-time analysis.

The FreeWAF provides specialized, layered application threat protection. It protects your web-based applications and internet-facing data from attack and data loss. Using advanced techniques to provide bidirectional protection against sophisticated threats like SQL injection and cross-site scripting, it helps you prevent identity theft, financial fraud and corporate espionage.

OctopusWAF is a open source Web application firewall, is made in C language uses libevent to make multiple connections. Event-driven architecture is optimized for a large number of parallel connections (keep-alive) which is important for high performance AJAX applications. This tool is very light, you can deploy in any please, this resource turn perfect to protect specific endpoint that need a custom protection.