What are the best tools and techniques for web application firewall testing and bypassing?

1 WAF basics

A web application firewall is a type of security software that monitors and filters incoming and outgoing web traffic, based on a set of rules and policies. WAFs can prevent or mitigate attacks such as SQL injection, cross-site scripting, remote file inclusion, and denial-of-service, by blocking or modifying malicious requests or responses. WAFs can be deployed as hardware appliances, software modules, or cloud-based services, and can operate at different layers of the network stack.

3 WAF evasion

Once the WAF is detected and identified, the next step is to find ways to evade or bypass it, by exploiting its weaknesses or limitations. Common evasion techniques include encoding, obfuscation, and encryption to transform the payload or request; tampering, manipulation, or injection to modify the payload or request; splitting, fragmentation, or chunking to divide the payload or request into smaller or multiple parts; and timing, sequencing, or concurrency to alter the timing or order of the payload or request. These techniques can be used to avoid triggering WAF rules and filters, confuse and mislead WAF logic and parsers, bypass WAF length and content restrictions, and evade WAF detection and prevention mechanisms.

4 WAF testing tools

Web application firewall testing and bypassing is an essential skill for infrastructure security professionals who wish to evaluate and enhance the security of web applications and their environments. There are many tools available for this purpose, such as Burp Suite, SQLmap, OWASP ZAP, and Nmap. Burp Suite is a powerful and versatile tool that enables intercepting, modifying, and replaying web requests and responses, as well as automated scans and fuzzing. SQLmap specializes in automating SQL injection detection and exploitation. OWASP ZAP is an open-source tool with a user-friendly interface and a wide range of features for WAF testing and bypassing. Finally, Nmap is a popular network security scanning tool that can also be used for WAF testing with its scripting engine and various scripts. By using the appropriate tools and techniques, professionals can identify and exploit vulnerabilities in web applications while bypassing or overcoming the protection of web application firewalls.