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ffuf - Fuzz Faster U Fool

A fast web fuzzer written in Go.


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

The only dependency of ffuf is Go 1.11. No dependencies outside of Go standard library are needed.

Example usage

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" -u https://target/login.php -fc 401

Maximum execution time

If you don't want ffuf to run indefinitely, you can use the -maxtime. This stops the entire process after a given time (in seconds).

ffuf -w /path/to/wordlist -u https://target/FUZZ -maxtime 60

When working with recursion, you can control the maxtime per job using -maxtime-job. This will stop the current job after a given time (in seconds) and continue with the next one. New jobs are created when the recursion functionality detects a subdirectory.

ffuf -w /path/to/wordlist -u https://target/FUZZ -maxtime-job 60 -recursion -recursion-depth 2

It is also possible to combine both flags limiting the per job maximum execution time as well as the overall execution time. If you do not use recursion then both flags behave equally.

Using external mutator to produce test cases

For this example, we'll fuzz JSON data that's sent over POST. Radamsa is used as the mutator.

When --input-cmd is used, ffuf will display matches as their position. This same position value will be available for the callee as an environment variable $FFUF_NUM. We'll use this position value as the seed for the mutator. Files example1.txt and example2.txt contain valid JSON payloads. We are matching all the responses, but filtering out response code 400 - Bad request:

ffuf --input-cmd 'radamsa --seed $FFUF_NUM example1.txt example2.txt' -H "Content-Type: application/json" -X POST -u -mc all -fc 400

It of course isn't very efficient to call the mutator for each payload, so we can also pre-generate the payloads, still using Radamsa as an example:

# Generate 1000 example payloads
radamsa -n 1000 -o %n.txt example1.txt example2.txt

# This results into files 1.txt ... 1000.txt
# Now we can just read the payload data in a loop from file for ffuf

ffuf --input-cmd 'cat $FFUF_NUM.txt' -H "Content-Type: application/json" -X POST -u -mc all -fc 400


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

Fuzz Faster U Fool - v1.0

  -H               Header `"Name: Value"`, separated by colon. Multiple -H flags are accepted.
  -X               HTTP method to use (default: GET)
  -b               Cookie data `"NAME1=VALUE1; NAME2=VALUE2"` for copy as curl functionality.
  -d               POST data
  -r               Follow redirects (default: false)
  -recursion       Scan recursively. Only FUZZ keyword is supported, and URL (-u) has to end in it. (default: false)
  -recursion-depth Maximum recursion depth. (default: 0)
  -replay-proxy    Replay matched requests using this proxy.
  -timeout         HTTP request timeout in seconds. (default: 10)
  -u               Target URL
  -x               HTTP Proxy URL

  -V               Show version information. (default: false)
  -ac              Automatically calibrate filtering options (default: false)
  -acc             Custom auto-calibration string. Can be used multiple times. Implies -ac
  -c               Colorize output. (default: false)
  -maxtime         Maximum running time in seconds for the entire process. (default: 0)
  -maxtime-job     Maximum running time in seconds per job. (default: 0)
  -p               Seconds of `delay` between requests, or a range of random delay. For example "0.1" or "0.1-2.0"
  -s               Do not print additional information (silent mode) (default: false)
  -sa              Stop on all error cases. Implies -sf and -se. (default: false)
  -se              Stop on spurious errors (default: false)
  -sf              Stop when > 95% of responses return 403 Forbidden (default: false)
  -t               Number of concurrent threads. (default: 40)
  -v               Verbose output, printing full URL and redirect location (if any) with the results. (default: false)

  -mc              Match HTTP status codes, or "all" for everything. (default: 200,204,301,302,307,401,403)
  -ml              Match amount of lines in response
  -mr              Match regexp
  -ms              Match HTTP response size
  -mw              Match amount of words in response

  -fc              Filter HTTP status codes from response. Comma separated list of codes and ranges
  -fl              Filter by amount of lines in response. Comma separated list of line counts and ranges
  -fr              Filter regexp
  -fs              Filter HTTP response size. Comma separated list of sizes and ranges
  -fw              Filter by amount of words in response. Comma separated list of word counts and ranges

  -D               DirSearch wordlist compatibility mode. Used in conjunction with -e flag. (default: false)
  -e               Comma separated list of extensions. Extends FUZZ keyword.
  -ic              Ignore wordlist comments (default: false)
  -input-cmd       Command producing the input. --input-num is required when using this input method. Overrides -w.
  -input-num       Number of inputs to test. Used in conjunction with --input-cmd. (default: 100)
  -mode            Multi-wordlist operation mode. Available modes: clusterbomb, pitchfork (default: clusterbomb)
  -request         File containing the raw http request
  -request-proto   Protocol to use along with raw request (default: https)
  -w               Wordlist file path and (optional) keyword separated by colon. eg. '/path/to/wordlist:KEYWORD'

  -debug-log       Write all of the internal logging to the specified file.
  -o               Write output to file
  -od              Directory path to store matched results to.
  -of              Output file format. Available formats: json, ejson, html, md, csv, ecsv (default: json)

  Fuzz file paths from wordlist.txt, match all responses but filter out those with content-size 42.
  Colored, verbose output.
    ffuf -w wordlist.txt -u -mc all -fs 42 -c -v

  Fuzz Host-header, match HTTP 200 responses.
    ffuf -w hosts.txt -u -H "Host: FUZZ" -mc 200

  Fuzz POST JSON data. Match all responses not containing text "error".
    ffuf -w entries.txt -u -X POST -H "Content-Type: application/json" \
      -d '{"name": "FUZZ", "anotherkey": "anothervalue"}' -fr "error"

  Fuzz multiple locations. Match only responses reflecting the value of "VAL" keyword. Colored.
    ffuf -w params.txt:PARAM -w values.txt:VAL -u -mr "VAL" -c

  More information and examples:

Helper scripts and advanced payloads

See ffuf-scripts repository for helper scripts and payload generators for different workflows and usage scenarios.


ffuf is released under MIT license. See LICENSE.

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