Cloudron 6.2 Cross Site Scripting

# Exploit Title: Cloudron 6.2 - Cross Site Scripting (Reflected)
# Google Dork: N/A
# Date: 10.06.2021
# Exploit Author: Akıner Kısa
# Vendor Homepage: https://cloudron.io
# Software Link: https://www.cloudron.io/get.html
# Version: 6.3 >
# Tested on: Demo / Localhost
# CVE : CVE-2021-31721
Proof of Concept:

1. Go to https://my.demo.cloudron.io/login.html?returnTo=

2. Type your payload after returnTo=

3. Fill in the login information and press the sign in button.