# CLZero | A Project For Fuzzing HTTP/1.1 CL.0 Request Smuggling Attack Vectors

**URL:** <https://onehack.st/t/clzero-a-project-for-fuzzing-http-1-1-cl-0-request-smuggling-attack-vectors/270402>\
**Category:** Tools & Scripts\
**Tags:** tools, hacking\
**Created:** [December 30, 2023, 7:12pm UTC](https://onehack.st/t/clzero-a-project-for-fuzzing-http-1-1-cl-0-request-smuggling-attack-vectors/270402 "2023-12-30T19:12:07Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![PlayBoy83](https://onehack.st/user_avatar/onehack.st/playboy83/32/164314_2.png) [@PlayBoy83](https://onehack.st/u/PlayBoy83)\
**Post date:** [December 30, 2023, 7:12pm UTC](https://onehack.st/t/clzero-a-project-for-fuzzing-http-1-1-cl-0-request-smuggling-attack-vectors/270402/1 "2023-12-30T19:12:08Z")

</div>

![image](https://onehack.st/uploads/default/original/3X/2/0/2086801ad9555d3ef2257133de59cefc7d0e595e.png)

# CLZero

A project for fuzzing HTTP/1.1 CL.0 Request Smuggling Attack Vectors.

# About

Thank you to @albinowax, @defparam and @d3d else this tool would not exist. Inspired by the tool [Smuggler](https://github.com/defparam/smuggler) all attack gadgets adapted from Smuggler and [https://portswigger.net/research/how-to-turn-security-research-into-profit](https://portswigger.net/research/how-to-turn-security-research-into-profit)

For more info see: [https://moopinger.github.io/blog/fuzzing/clzero/tools/request/smuggling/2023/11/15/Fuzzing-With-CLZero.html](https://moopinger.github.io/blog/fuzzing/clzero/tools/request/smuggling/2023/11/15/Fuzzing-With-CLZero.html)

# Usage

```auto
usage: clzero.py [-h] [-url URL] [-file FILE] [-index INDEX] [-verbose] [-no-color] [-resume] [-skipread] [-quiet] [-lb] [-config CONFIG] [-method METHOD]

CLZero by Moopinger

optional arguments:
  -h, --help show this help message and exit
  -url URL (-u), Single target URL.
  -file FILE (-f), Files containing multiple targets.
  -index INDEX (-i), Index start point when using a file list. Default is first line.
  -verbose (-v), Enable verbose output.
  -no-color Disable colors in HTTP Status
  -resume Resume scan from last index place.
  -skipread Skip the read response on smuggle requests, recommended. This will save a lot of time between requests. Ideal for targets with standard HTTP traffic.
  -quiet (-q), Disable output. Only successful payloads will be written to ./payloads/
  -lb Last byte sync method for least request latency. Due to the nature of the request, it cannot guarantee that the smuggle request will be processed first. Ideal for targets with a high
                  amount of traffic, and you do not mind sending multiple requests.
  -config CONFIG (-c) Config file to load, see ./configs/ to create custom payloads
  -method METHOD (-m) Method to use when sending the smuggle request. Default: POST

```

single target attack:

- `python3 clzero.py -u https://www.target.com/ -c configs/default.py -skipread`
- `python3 clzero.py -u https://www.target.com/ -c configs/default.py -lb`

Multi target attack:

- `python3 clzero.py -l urls.txt -c configs/default.py -skipread`
- `python3 clzero.py -l urls.txt -c configs/default.py -lb`

# Install

```auto
git clone https://github.com/Moopinger/CLZero.git
cd CLZero
pip3 install -r requirements.txt

```

## GitHub:

> **[GitHub - Moopinger/CLZero: A project for fuzzing HTTP/1.1 CL.0 Request...](https://github.com/Moopinger/CLZero)**
>
> A project for fuzzing HTTP/1.1 CL.0 Request Smuggling Attack Vectors