OverReacher - A Convenient CORS Scanner

OverReacher is a security research tool, meant to scan and find CORS misconfiguration vulnerabilities.

Made this tool based on functionality from Corsy

Getting Started

Pipx install

OverReacher can be easily installed using:

pipx install overreacher

Afterwards you can check the usage with:

overreacher.py -h

Pip install

A normal pip install also works:

pip install overreacher

But, unless it's a global install, which is not recommended, you need to do additional setup on your own

Manual install

Instead of installing the package using pip or pipx, OverReacher can be setup manually. Just git clone the repo and then do the following:

Setup a virtual environment using the tool you prefer (venv in this case), and activate it

python3 -m venv ./venv
source venv/bin/activate

Then install the base requirements

pip install -r requirements.txt

Afterwards you can run overreacher in the following ways:

python3 -m overreacher

Or through the run script, which you can alias or symlink to your liking:

chmod +x ./run
./run -h

NOTE: To run you still need to use the virtual environments python interpreter

Configuration

OverReacher is made to be easily customizable. This is incredibly helpful in BugBounty, where you might say, want to customize headers/cookies depending on the target. (eg. Setting a hackerone header, which some programs require)

In addition to configuration in the config.ini file, you can also customize attacks and add your own in the attacks.json file.

To make a new configuration, simply run

overreacher --make-config

This will make a local .overreacher directory which the tool will automatically be setup to use. If the directory already exists, it will be set as the configuration of the tool with no additional changes.

In this fashion you can change configurations depending on your needs and projects, and reset to normal with:

overreacher --reset-config

Usage

An attack can be tested against a certain url or a comma separated list of urls as such:

overreacher -u https://example.com/,https://google.com/

Alternatively the url's can be loaded from a file

overreacher.py -i [FILE]

Or piped through stdin

cat exampleurlfile.txt | overreacher

TODO:

In TODO.md