Technically, it is a third-party Nginx module, available as a package for many UNIX-like platforms. This module, by default, reads a small subset of simple (and readable) rules containing 99% of known patterns involved in website vulnerabilities. For example, <, | or drop are not supposed to be part of a URI. Being very simple, those patterns may match legitimate queries, it is Naxsi's administrator duty to add specific rules that will whitelist legitimate behaviors. The administrator can either add whitelists manually by analyzing nginx's error log, or (recommended) start the project with an intensive auto-learning phase that will automatically generate whitelisting rules regarding a website's behavior. In short, Naxsi behaves like a DROP-by-default firewall, the only task is to add required ACCEPT rules for the target website to work properly.
Features
- NAXSI means Nginx Anti XSS & SQL Injection
- Contrary to most Web Application Firewalls, Naxsi doesn't rely on a signature base like an antivirus
- Naxsi should be compatible with any nginx version
- It is the Naxsi's administrator duty to add specific rules that will whitelist legitimate behaviors
- The administrator can add whitelists manually by analyzing nginx's error log
- Naxsi behaves like a DROP-by-default firewall