Firefly - Black Box Fuzzer For Web Applications

Firefly is an advanced black-box fuzzer and not just a standard asset discovery tool. Firefly provides the advantage of testing a target with a large number of built-in checks to detect behaviors in the target.


Firefly is in a very new stage (v1.0) but works well for now, if the target does not contain too much dynamic content. Firefly still detects and filters dynamic changes, but not yet perfectly.



  • Hevy use of gorutines and internal hardware for great preformance
  • Built-in engine that handles each task for "x" response results inductively
  • Highly cusomized to handle more complex fuzzing
  • Filter options and request verifications to avoid junk results
  • Friendly error and debug output
  • Build in payloads (default list are mixed with the wordlist from seclists)
  • Payload tampering and encoding functionality



go install -v

If the above install method do not work try the following:

git clone
cd firefly/
go build cmd/firefly/firefly.go
./firefly -h



firefly -h
firefly -u ''

Advanced usage


Different types of request input that can be used


firefly -u '' --timeout 7000

Request with different methods and protocols

firefly -u '' -m GET,POST,PUT -p https,http,ws


echo '' | firefly 


firefly -r '
GET /?query=FUZZ HTTP/1.1
User-Agent: FireFly'

This will send the HTTP Raw and auto detect all GET and/or POST parameters to fuzz.

firefly -r '
POST /?A=1 HTTP/1.1
User-Agent: Firefly
X-Host: FUZZ

B=2&C=3' -au replace

Request Verifier

Request verifier is the most important part. This feature let Firefly know the core behavior of the target your fuzz. It's important to do quality over quantity. More verfiy requests will lead to better quality at the cost of internal hardware preformance (depending on your hardware)

firefly -u '' -e 


Payload can be highly customized and with a good core wordlist it's possible to be able to fully adapt the payload wordlist within Firefly itself.

Payload debug

Display the format of all payloads and exit

firefly -show-payload


List of all Tampers avalible

firefly -list-tamper

Tamper all paylodas with given type (More than one can be used separated by comma)

firefly -u '' -e s2c


firefly -u '' -e hex

Hex then URL encode all payloads

firefly -u '' -e hex,url

Payload regex replace

firefly -u '' -pr '\([0-9]+=[0-9]+\) => (13=(37-24))'

The Payloads: ' or (1=1)-- - and " or(20=20)or " Will result in: ' or (13=(37-24))-- - and " or(13=(37-24))or " Where the => (with spaces) inducate the "replace to".


Filter options to filter/match requests that include a given rule.

Filter response to ignore (filter) status code 302 and line count 0

firefly -u '' -fc 302 -fl 0

Filter responses to include (match) regex, and status code 200

firefly -u '' -mr '[Ee]rror (at|on) line \d' -mc 200
firefly -u '' -mr 'MySQL' -mc 200


Preformance and time delays to use for the request process

Threads / Concurrency

firefly -u '' -t 35

Time Delay in millisecounds (ms) for each Concurrency

FireFly -u '' -t 35 -dl 2000


Wordlist that contains the paylaods can be added separatly or extracted from a given folder

Single Wordlist with its attack type

firefly -u '' -w wordlist.txt:fuzz

Extract all wordlists inside a folder. Attack type is depended on the suffix <type>_wordlist.txt

firefly -u '' -w wl/


Wordlists names inside folder wl :

  1. fuzz_wordlist.txt
  2. time_wordlist.txt


JSON output is strongly recommended. This is because you can benefit from the jq tool to navigate throw the result and compare it.

(If Firefly is pipeline chained with other tools, standard plaintext may be a better choice.)

Simple plaintext output format

firefly -u '' -o file.txt

JSON output format (recommended)

firefly -u '' -oJ file.json


Everyone in the community are allowed to suggest new features, improvements and/or add new payloads to Firefly just make a pull request or add a comment with your suggestions!

Firefly - Black Box Fuzzer For Web Applications Firefly - Black Box Fuzzer For Web Applications Reviewed by Zion3R on 8:30 AM Rating: 5