PHProjekt PhpSimplyGest / MyProjects 1.3.0 Cross Site Scripting Vulnerability

# Exploit Title: PHProjekt (PhpSimplyGest / MyProjects, 1.3.0) - Stored XSS (Cross-Site Scripting)
# Exploit Author: Andrea Intilangelo
# Vendor Homepage: http://www.phprojekt.altervista.org (removed demo was at http://phprojekt.altervista.org/phpsimplygest130)
# Software Link: https://github.com/robyfofo/MyProjects (original PhpSimplyGest https://github.com/robyfofo/PhpSimplyGest now merged/renamed into MyProjects)
# Version: 1.3
# Tested on: Latest Version of Desktop Web Browsers (ATTOW: Firefox 100.0, Microsoft Edge 101.0.1210.32)
# CVE: CVE-2022-27308


Description:

A stored cross-site scripting (XSS) vulnerability in PHProjekt PhpSimplyGest v1.3.0 (and related products from same vendor, like "MyProjects") allows
attacker to execute arbitrary web scripts or HTML.

Injecting persistent javascript code inside the title description (or content) while creating a project, todo, timecard, estimates, report or finding,
it will be triggered once page gets loaded.


Steps to reproduce:

Click on Projects and add or edit an existing one,

Insert the following PoC inside the Title

   <<SCRIPT>alert("XSS here");//\<</SCRIPT>

Click on 'Send'.

If a user visits the website dashboard, as well as project summary page, the javascript code will be rendered.


Timeline:

2022-01-08: Vulnerability discovered.
2022-01-08: Vendor contacted.
2022-02-09: No reply, vendor contacted for 2nd time.
2022-02-18: Request for CVE reservation.
2022-04-27: Assigned CVE number 2022-27308.
2022-05-02: No reply, vendor contacted for 3rd time.
2022-05-05: Public disclosure.


PoC Screenshots:

https://imagebin.ca/v/6g5OFET1pyZB
https://imagebin.ca/v/6g6qLRC3X5ky
https://postimg.cc/qgc19rg0