# Exploit Title: Google Invisible RECAPTCHA 3 - Spoof Bypass # Date: 2020-02-07 # Vendor Homepage: https://developers.google.com/recaptcha/docs/invisible # Exploit Git Repo: https://github.com/matamorphosis/Browser-Exploits/tree/master/RECAPTCHA_Bypass # Exploit Author: Matamorphosis # Tested on: Windows and Ubuntu 19.10 # Category: Web Apps -------------------------------------------------------------------------------------------- RECAPTCHA Bypass: -------------------------------------------------------------------------------------------- This tool allows a user to bypass Version 3 of Google's Invisible RECAPTCHA by creating a spoofed web app that leverages the same RECAPTCHA, by providing the victims site key. What makes a site vulnerable? 1. They are using Version 3 of Google's Invisible RECAPTCHA 2. They allow the site key to be used on "localhost". However, while currently untested you could try adding the DNS name of the target you are attacking and try resolving it to 127.0.0.1 in your hosts file. NOTE: Exploit users need to have a functional understanding of both Python and JavaScript to make the necessary changes to run this exploit. -------------------------------------------------------------------------------------------- PREREQUISITES: -------------------------------------------------------------------------------------------- The instructions supplied are written for Debian-based Linux distributions. However, this can be setup on any OS with relative ease. 1. Download and install Firefox located at https://www.mozilla.org/en-US/firefox/new/ 2. Download Gecko Driver located at https://github.com/mozilla/geckodriver/releases and ensure the binary is in your path. For *nux just copy the file to /usr/bin ``` user@linux:~$ sudo cp geckodriver /usr/bin/geckodriver ``` 3. To use this exploit, you need to install python3, pip3 and install the additional requirements that are in the requirements.txt file. ``` user@linux:~$ sudo apt install python3 python3-pip -y ``` 4. Now install the prerequisistes ``` user@linux:~$ pip3 install -r requirements.txt ``` -------------------------------------------------------------------------------------------- USAGE: -------------------------------------------------------------------------------------------- 1. Obtain the site key from the target web application. There should be JavaScript that looks like the following - use the inspect element function to view it, there are two locations you can grab the site key: ``` ``` 2. Open the index.html file and paste the Site Key into the appropriate locations. 3. This next part is where it gets a little tricky. You need to replicate the form you are attacking and change a few things. Firstly in the body of the index.html file. Ensure you are using the appropriate method "GET" or "POST" and you are submitting it to the correct destination. ``` ``` *For steps 4-6, example code has been provided already, but ensure it matches the site you are targetting. It may be easier to strip it out and follow 4-6 if you are having a difficult time getting it working.* 4. Next you will need to add the following lines to the body of the JavaScript already inside of the