GigToDo 1.3 - Cross-Site Scripting

# Exploit Title: GigToDo - Freelance Marketplace Script v1.3 Persistent XSS Injection
# Google Dork: -
# Date: 2019/07/28
# Author: m0ze
# Vendor Homepage: https://www.gigtodoscript.com
# Software Link: https://codecanyon.net/item/gigtodo-freelance-marketplace-script/23855397
# Version: <= 1.3
# Tested on: NginX/1.15.10
# CVE: -
# CWE: CWE-79


Details & Description:
The «GigToDo - Freelance Marketplace Script» web-application is vulnerable
to reflected and persistent XSS injections that allows an attacker to
inject JavaScript/HTML code into the front-end, redirect visitor to another
website or steal admin cookies.


PoC [Persistent XSS Injection]:
Register a new account, log in and go to the
https://www.site.com/proposals/create_proposal page. Vulnerable text area
is «Proposal's Description», so paste your payload inside, fill in other
fields and save the data TWICE or your payload WILL NOT WORK. So literally
paste your payload inside the «Proposal's Description» text area and scroll
down to «Update Proposal» button, press it and your data will be saved.
After that u'll be redirected to
https://www.site.com/proposals/view_proposals.php page. Select your created
proposal and press green square dropdown menu on the right («Actions»
column) and click on «Edit» link. After that just don't change anything,
scroll down to «Update Proposal» button, press it and your data will be
saved ONE MORE TIME. That's it, now your payload will work.
Example #1: <h1
onmouseover=';alert(`m0ze`);'>m0ze</h1>1"--><svg/onload=';alert(`Script is
fully protected from SQL Injection and XSS ©`);'><img src='x'
onerror=';alert(`For sure lol`);'>
Example #2: <h1 onmouseover=';alert(`Greetz from
m0ze`);'>m0ze</h1>1"--><svg/onload=';window.location.replace(`
https://twitter.com/m0ze_ru`);'>