/ffuf

Fast web fuzzer written in Go

Primary LanguageGoMIT LicenseMIT

ffuf mascot

ffuf - Fuzz Faster U Fool

A fast web fuzzer written in Go.

Installation

  • Download a prebuilt binary from releases page, unpack and run!

    or

  • If you are on macOS with homebrew, ffuf can be installed with: brew install ffuf

    or

  • If you have recent go compiler installed: go install github.com/ffuf/ffuf/v2@latest (the same command works for updating)

    or

  • git clone https://github.com/ffuf/ffuf ; cd ffuf ; go get ; go build

Ffuf depends on Go 1.16 or greater.

Example usage

The usage examples below show just the simplest tasks you can accomplish using ffuf.

More elaborate documentation that goes through many features with a lot of examples is available in the ffuf wiki at https://github.com/ffuf/ffuf/wiki

For more extensive documentation, with real life usage examples and tips, be sure to check out the awesome guide: "Everything you need to know about FFUF" by Michael Skelton (@codingo).

You can also practise your ffuf scans against a live host with different lessons and use cases either locally by using the docker container https://github.com/adamtlangley/ffufme or against the live hosted version at http://ffuf.me created by Adam Langley @adamtlangley.

Typical directory discovery

asciicast

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)

asciicast

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 a 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 https://ffuf.io.fi/FUZZ -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 https://ffuf.io.fi/ -mc all -fc 400

Configuration files

When running ffuf, it first checks if a default configuration file exists. Default path for a ffufrc file is $XDG_CONFIG_HOME/ffuf/ffufrc. You can configure one or multiple options in this file, and they will be applied on every subsequent ffuf job. An example of ffufrc file can be found here.

A more detailed description about configuration file locations can be found in the wiki: https://github.com/ffuf/ffuf/wiki/Configuration

The configuration options provided on the command line override the ones loaded from the default ffufrc file. Note: this does not apply for CLI flags that can be provided more than once. One of such examples is -H (header) flag. In this case, the -H values provided on the command line will be appended to the ones from the config file instead.

Additionally, in case you wish to use bunch of configuration files for different use cases, you can do this by defining the configuration file path using -config command line flag that takes the file path to the configuration file as its parameter.

Usage

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 - v2.1.0

HTTP OPTIONS:
  -H                  Header `"Name: Value"`, separated by colon. Multiple -H flags are accepted.
  -X                  HTTP method to use
  -b                  Cookie data `"NAME1=VALUE1; NAME2=VALUE2"` for copy as curl functionality.
  -cc                 Client cert for authentication. Client key needs to be defined as well for this to work
  -ck                 Client key for authentication. Client certificate needs to be defined as well for this to work
  -d                  POST data
  -http2              Use HTTP2 protocol (default: false)
  -ignore-body        Do not fetch the response content. (default: false)
  -r                  Follow redirects (default: false)
  -raw                Do not encode URI (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)
  -recursion-strategy Recursion strategy: "default" for a redirect based, and "greedy" to recurse on all matches (default: default)
  -replay-proxy       Replay matched requests using this proxy.
  -sni                Target TLS SNI, does not support FUZZ keyword
  -timeout            HTTP request timeout in seconds. (default: 10)
  -u                  Target URL
  -x                  Proxy URL (SOCKS5 or HTTP). For example: http://127.0.0.1:8080 or socks5://127.0.0.1:8080

GENERAL OPTIONS:
  -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
  -ach                Per host autocalibration (default: false)
  -ack                Autocalibration keyword (default: FUZZ)
  -acs                Custom auto-calibration strategies. Can be used multiple times. Implies -ac
  -c                  Colorize output. (default: false)
  -config             Load configuration from a file
  -json               JSON output, printing newline-delimited JSON records (default: false)
  -maxtime            Maximum running time in seconds for entire process. (default: 0)
  -maxtime-job        Maximum running time in seconds per job. (default: 0)
  -noninteractive     Disable the interactive console functionality (default: false)
  -p                  Seconds of `delay` between requests, or a range of random delay. For example "0.1" or "0.1-2.0"
  -rate               Rate of requests per second (default: 0)
  -s                  Do not print additional information (silent mode) (default: false)
  -sa                 Stop on all error cases. Implies -sf and -se. (default: false)
  -scraperfile        Custom scraper file path
  -scrapers           Active scraper groups (default: all)
  -se                 Stop on spurious errors (default: false)
  -search             Search for a FFUFHASH payload from ffuf history
  -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)

MATCHER OPTIONS:
  -mc                 Match HTTP status codes, or "all" for everything. (default: 200-299,301,302,307,401,403,405,500)
  -ml                 Match amount of lines in response
  -mmode              Matcher set operator. Either of: and, or (default: or)
  -mr                 Match regexp
  -ms                 Match HTTP response size
  -mt                 Match how many milliseconds to the first response byte, either greater or less than. EG: >100 or <100
  -mw                 Match amount of words in response

FILTER OPTIONS:
  -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
  -fmode              Filter set operator. Either of: and, or (default: or)
  -fr                 Filter regexp
  -fs                 Filter HTTP response size. Comma separated list of sizes and ranges
  -ft                 Filter by number of milliseconds to the first response byte, either greater or less than. EG: >100 or <100
  -fw                 Filter by amount of words in response. Comma separated list of word counts and ranges

INPUT OPTIONS:
  -D                  DirSearch wordlist compatibility mode. Used in conjunction with -e flag. (default: false)
  -e                  Comma separated list of extensions. Extends FUZZ keyword.
  -enc                Encoders for keywords, eg. 'FUZZ:urlencode b64encode'
  -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)
  -input-shell        Shell to be used for running command
  -mode               Multi-wordlist operation mode. Available modes: clusterbomb, pitchfork, sniper (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'

OUTPUT OPTIONS:
  -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 (or, 'all' for all formats) (default: json)
  -or                 Don't create the output file if we don't have results (default: false)

EXAMPLE USAGE:
  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 https://example.org/FUZZ -mc all -fs 42 -c -v

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

  Fuzz POST JSON data. Match all responses not containing text "error".
    ffuf -w entries.txt -u https://example.org/ -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 https://example.org/?PARAM=VAL -mr "VAL" -c

  More information and examples: https://github.com/ffuf/ffuf

Interactive mode

By pressing ENTER during ffuf execution, the process is paused and user is dropped to a shell-like interactive mode:

entering interactive mode
type "help" for a list of commands, or ENTER to resume.
> help

available commands:
 afc  [value]             - append to status code filter 
 fc   [value]             - (re)configure status code filter 
 afl  [value]             - append to line count filter 
 fl   [value]             - (re)configure line count filter 
 afw  [value]             - append to word count filter 
 fw   [value]             - (re)configure word count filter 
 afs  [value]             - append to size filter 
 fs   [value]             - (re)configure size filter 
 aft  [value]             - append to time filter 
 ft   [value]             - (re)configure time filter 
 rate [value]             - adjust rate of requests per second (active: 0)
 queueshow                - show job queue
 queuedel [number]        - delete a job in the queue
 queueskip                - advance to the next queued job
 restart                  - restart and resume the current ffuf job
 resume                   - resume current ffuf job (or: ENTER) 
 show                     - show results for the current job
 savejson [filename]      - save current matches to a file
 help                     - you are looking at it
> 

in this mode, filters can be reconfigured, queue managed and the current state saved to disk.

When (re)configuring the filters, they get applied posthumously and all the false positive matches from memory that would have been filtered out by the newly added filters get deleted.

The new state of matches can be printed out with a command show that will print out all the matches as like they would have been found by ffuf.

As "negative" matches are not stored to memory, relaxing the filters cannot unfortunately bring back the lost matches. For this kind of scenario, the user is able to use the command restart, which resets the state and starts the current job from the beginning.

License

ffuf is released under MIT license. See LICENSE.