QuicDraw (H3)

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    QuicDraw(H3): HTTP/3 Fuzzing and Racing (Client)
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               _         _
              (_)       | |                          ______
    __ _ _   _ _  ___ __| |_ __ __ ___      __  /\  /\___ /
   / _` | | | | |/ __/ _` | '__/ _` \ \ /\ / / / /_/ / |_ \
  | (_| | |_| | | (_| (_| | | | (_| |\ V  V / / __  / ___) |
   \__, |\__,_|_|\___\__,_|_|  \__,_| \_/\_/  \/ /_/ |____/
      |_|    _______
         \  |QFS____| -------------------- HTTP/3
          \ |_//
            |_|

    GitHub: https://github.com/cyberark/QuicDrawH3
    License: Apache-2.0 License
    Author: Maor Abutbul <CyberArk Labs>
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QuicDraw is a security research tool designed for fuzzing and racing HTTP/3 servers. QuicDraw implements the Quic-Fin-Sync on HTTP/3 (over QUIC), for race-condition testing.

The tool was originally published as part of CyberArk Labs' research: "Racing and Fuzzing HTTP/3: Open-sourcing QuicDraw(H3)"

TOC

• QuicDraw
  • Main Features
  • Quick Start
    • Install using pip
    • Build and install locally by cloning the source (optional)
  • Usage
    • Print Help
    • Normal HTTP/3 (over QUIC) Requests
    • Log TLS Secrets to file -l SECRETS_LOG
    • Verbose logging -v
    • Testing Race-Conditions in HTTP3 applications -tr TOTAL_REQUESTS
      • Racing example
    • Fuzzing HTTP3 applications -d DATA -w WORDLIST
      • Fuzzing Example
  • Contributing
  • Limitations
  • Known issues
  • License
  • Contact
    • Contact Via LinkedIn

 Main Features

• Implements the Quic-Fin-Sync on HTTP3 (over QUIC), for race-condition testing.
• Supports fuzzing multiple requests with the FUZZ and wordlist (-w argument) mechanisms.
• Custom HTTP headers functionality (-H argument).
  • Note: Custom headers are converted to lowercase since we have seen issues with some server implementations.
• Supports SSLKEYLOGFILE (-l argument) for TLS decryption/inspection via packet analyzers such as Wireshark.
• Based on aioquic (http3_client)
  • aioquic is a library for the QUIC network protocol in Python.
  • It features a minimal TLS 1.3 implementation, a QUIC stack, and an HTTP/3 stack.

Quick Start

Prerequisite:

• python >=3.9
• pip3

Install using pip

The easiest way to install QuicDraw is to run:

pip install quicdraw

Runninig (after pip install)

quicdraw -h

Build and install locally by cloning the source (optional)

If there are no wheels for your system or if you wish to build QuicDraw from source.

Clone the repository:

git clone https://github.com/cyberark/quicdrawh3.git
python3 -m build
pip install .\dist\quicdraw-<VERSION>.tar.gz

Install module dependencies. (You may prefer to do this within a Virtual Environment)

Usage

Print Help

quicdraw -h

Normal HTTP/3 (over QUIC) Requests

An HTTP/3 GET Request

quicdraw <https://http3_server.com/path>

An HTTP/3 POST Request

HTTP POST requests are determined by using the -d argument followed by the HTTP POST data to be sent.

quicdraw <https://http3_server.com/path> -d '{"key":"value"}'

Log TLS Secrets to file -l SECRETS_LOG

log secrets to a file, for use with Wireshark

To inspect the traffic in wireshark: Open Wireshark → Edit → Preferences → Protocols → TLS and set “(Pre)-Master-Secret log filename” to the full path of secrets.log

Verbose logging -v

Using the verbose (-v) output will log (print) the request data to be sent and the HTTP response content.

In the case of GET requests (no -d argument supplied), the request URL (:path) will be logged (printed).

Testing Race-Conditions in HTTP3 applications -tr TOTAL_REQUESTS

To use the same request multiple times (using the Quic-Fin-Sync / single-packet), use the -tr/--total-requests argument.

Note: If a WORDLIST (-w) argument is specified, this argument (-tr TOTAL_REQUESTS) is overridden by the wordlist number of lines.

Racing example

Repeat the same request 12 times (-tr 12) (using Quic-Fin-Sync)

quicdraw <https://http3_server.com/path> -d '{"key":"value"}' -H 'Authorization: bearer eyJ...' -tr 12

Repeat the same request 12 times (-tr 12), use Quic-Fin-Sync and log (-l) TLS secrets

quicdraw <https://http3_server.com/path> -d '{"key":"value"}' -H 'Authorization: bearer eyJ...' -H 'content-type: application/json' -l /m2a/ssl_key_log_file.log -tr 12

Repeat the same request 12 times (-tr 12), use Quic-Fin-Sync, log (-l) TLS secrets, and print verbose (-v) output including HTTP response content

quicdraw <https://http3_server.com/path> -d '{"key": "value"}' -H 'Authorization: bearer eyJ...' -H 'content-type: application/json' -l /m2a/ssl_key_log_file.log -tr 12 -v

Fuzzing HTTP3 applications -d DATA -w WORDLIST

Fuzzing in QuicDraw is based on a simple concept, like other web fuzzers (Ffuf, Wfuzz), go over the data section (-d), and replace any reference to the FUZZ keyword with the value given in the wordlist (-w) as the payload.

To define fuzzing, use the wordlist (-w/--wordlist) argument with the FUZZ keyword anywhere in the DATA (-d argument) section.

Note: If the payload (-d) does not include the FUZZ keyword, the same data will be sent according to the number of lines in the wordlist file.

Fuzzing Example

Use Quic-Fin-Sync, go over the data section (-d), and replace any reference to the FUZZ keyword with the value given in the wordlist file (-w) as the payload

quicdraw <https://http3_server.com/path> -w path/to/wordlist -d '{"example_key":"FUZZ"}'

Contributing

We welcome contributions of all kinds to this repository. For instructions on how to get started and descriptions of our development workflows, please see our contributing guide

Limitations

• The Quic-Fin-Sync is mostly effective in POST requests (using the -d argument).
  • GET requests will benefit from the mechanism, but according to our tests, only a few requests "fit" on a single QUIC packet.
• The fuzzing mechanism (FUZZ and --wordlist/-w) only works in POST messages data or in the GET request URL (:path) argument.
• Currently, the fuzzing mechanism only works once, meaning if the data argument is supplied (-d), we assume fuzzing on the POST data, supplying the FUZZ keyword in the URL (:path) will result in sending the URL (:path) as-is (including the FUZZ keyword).
• We do not support multiple different domains in the current version. (For different paths, you can use the FUZZ keyword in the URL's path part)

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Known issues

• "socket.gaierror: [Errno 11001] getaddrinfo failed" error returned on DNS error

License

Copyright (c) 2025 CyberArk Software Ltd. All rights reserved This repository is licensed under the Apache-2.0 License - see LICENSE for more details.

Contact

Feel free to contact us via GitHub issues if you have any feature requests or project issues.

Contact Via LinkedIn

Maor Abutbul