ffuf (Fuzz Faster U Fool) is a fast and versatile web fuzzer written in Go that can help security professionals uncover hidden directories, parameters, and vulnerabilities in web applications. In this post, we’ll dive into how ffuf can be used for efficient fuzzing and reveal some lesser-known techniques to elevate your testing game.
1. Getting Started with ffuf
The simplest use-case for ffuf is to discover directories on a target web server. By using a wordlist, you can quickly scan for common directories or files:
ffuf -u http://target.com/FUZZ -w /path/to/wordlist.txtThis command replaces FUZZ with entries from your wordlist, returning any discovered directories or files.
2. Advanced Output Filtering
ffuf offers robust filtering options to help you focus on the most relevant results. You can filter by HTTP status codes, response size, and even word count. For instance:
ffuf -u http://target.com/FUZZ -w /path/to/wordlist.txt -mc 200,204,301,302,307,403This command only displays responses with the specified status codes, cutting through the noise and reducing false positives.
3. Recursive Fuzzing: Digging Deeper
One of ffuf’s underutilized features is recursive fuzzing. Once a directory is discovered, you can automatically fuzz it for more hidden content by enabling recursion:
ffuf -u http://target.com/FUZZ -w /path/to/wordlist.txt -recursionThis flag recursively appends wordlist entries to any discovered directories, revealing nested structures that might be overlooked during a basic scan.
4. Parameter Fuzzing for Web Applications
ffuf isn’t limited to directories. You can also fuzz HTTP parameters to uncover vulnerabilities in web forms or APIs. For example:
ffuf -u "http://target.com/page.php?param=FUZZ" -w /path/to/param-wordlist.txtThis method can help reveal issues such as SQL injection points, XSS vulnerabilities, or unexpected input handling, providing deeper insight into the target application.
5. Integration and Automation
ffuf’s output is designed for easy integration into your workflow. You can pipe the results into other tools for further analysis or export them as structured data for reporting. By automating ffuf with custom scripts, you can streamline the reconnaissance phase and allocate more time to analyzing and exploiting identified weaknesses.
Final Thoughts
ffuf is a powerful tool that, when used effectively, can expose hidden corners of web applications that might otherwise go unnoticed. From advanced filtering and recursive fuzzing to parameter testing, its diverse features make it an essential component in any security tester’s arsenal. As always, ensure you have proper authorization before scanning or fuzzing any system.
Happy fuzzing!