ffuf - Fuzz Faster U Fool

A fast web fuzzer written in Go.

Heavily inspired by the great projects gobuster and wfuzz.

Features

• Fast!
• Allows fuzzing of HTTP header values, POST data, and different parts of URL, including GET parameter names and values
• Silent mode (-s) for clean output that's easy to use in pipes to other processes.
• Modularized architecture that allows integration with existing toolchains with reasonable effort
• Easy-to-add filters and matchers (they are interoperable)

Example cases

Typical directory discovery

By using the FUZZ keyword at the end of URL (-u):

ffuf -w /path/to/wordlist -u https://target/FUZZ

Virtual host discovery (without DNS records)

Assuming that the default virtualhost response size is 4242 bytes, we can filter out all the responses of that size (-fs 4242)while fuzzing the Host - header:

ffuf -w /path/to/vhost/wordlist -u https://target -H "Host: FUZZ" -fs 4242

GET parameter fuzzing

GET parameter name fuzzing is very similar to directory discovery, and works by defining the FUZZ keyword as a part of the URL. This also assumes an response size of 4242 bytes for invalid GET parameter name.

ffuf -w /path/to/paramnames.txt -u https://target/script.php?FUZZ=test_value -fs 4242

If the parameter name is known, the values can be fuzzed the same way. This example assumes a wrong parameter value returning HTTP response code 401.

ffuf -w /path/to/values.txt -u https://target/script.php?valid_name=FUZZ -fc 401

POST data fuzzing

This is a very straightforward operation, again by using the FUZZ keyword. This example is fuzzing only part of the POST request. We're again filtering out the 401 responses.

ffuf -w /path/to/postdata.txt -X POST -d "username=admin\&password=FUZZ" https://target/login.php -fc 401

Usage

To define the test case for ffuf, use the keyword FUZZ anywhere in the URL (-u), headers (-H), or POST data (-d).

Usage of ./ffuf:
  -H value
    	Header name and value, separated by colon. Multiple -H flags are accepted.
  -X string
    	HTTP method to use. (default "GET")
  -c	Colorize output.
  -d string
    	POST data.
  -fc string
    	Filter HTTP status codes from response
  -fs string
    	Filter HTTP response size
  -k	Skip TLS identity verification (insecure)
  -mc string
    	Match HTTP status codes from respose (default "200,204,301,302,307,401")
  -ms string
    	Match HTTP response size
  -s	Do not print additional information (silent mode)
  -t int
    	Number of concurrent threads. (default 20)
  -u string
    	Target URL
  -w string
    	Wordlist path

eg. ffuf -u https://example.org/FUZZ -w /path/to/wordlist

Installation

• Download a prebuilt binary from releases page, unpack and run! or
• If you have go compiler installed: go get github.com/ffuf/ffuf

TODO

• Tests!
• Filters: word count, regex
• Option to follow redirects
• Optional scope for redirects
• Client / server architecture to queue jobs and fetch the results later
• Fuzzing multiple values at the same time
• Output module for file writing in different formats: csv, json
• Output module to push the results to an HTTP API