PHP Remote File Inclusion vulnerability scanner

PHP Code


<?php 
<html>
   <head>
      <title>RFI Vulnerability Scanner</title>
      <style>
      body {
      background-color: grey;
      text-align: center;
      color: black;
      }
      </style>
   </head>

   <body>
      <h1>RFI Vulnerability Scanner</h1>
      <form method="POST" action="">
      Website:
      <input type="text" name="url" value="http://www.site.com/index.php?id=" size="55" />
      <input type="submit" name="submit" value="Scan" />
      </form>  

      <?php
      class rfivulnscanner
      {
             private $rfiinclude  = array("http://www.facebook.com");
             private $rfierrors   = array("Welcome to Facebook - Log In, Sign Up or Learn More");

             function valid($website){
            if(filter_var($website,FILTER_VALIDATE_URL) && strstr($website,"="))
             return true;
             return false;
             }

             function contents($website) {
            $agent= 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0';
            $che = curl_init();
            curl_setopt($che, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($che, CURLOPT_VERBOSE, true);
            curl_setopt($che, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($che, CURLOPT_USERAGENT, $agent);
            curl_setopt($che, CURLOPT_URL,$website);
            $result=@curl_exec($che);
            return $result;
             }

             function checkerror($url,$add,$errorar) {
            foreach($add as $val)
             {
            $website = $url.$val;
            $contents = $this->contents($website);
             foreach($errorar as $err)
            {
             if(strstr($contents, $err))
             return true;
            }
             }
            return false;
             }

             function rfivulnerable($website) {
            $web = $website;
            $website = substr($website,0,strpos($website,'=')+1);
             if($this->checkerror($website,$this->rfiinclude,$this->rfierrors)) 
            echo htmlentities($web) ." <span style=\"color: green;\">might</span> be vulnerable to RFI.<br />";
             else
            echo htmlentities($web) ." is probably <span style=\"color: red;\">NOT</span> vulnerable to RFI.<br />";
             }
             }

             if(isset($_POST['url']) && isset($_POST['submit']))
            {
             $obs = new rfivulnscanner();
             $website = $_POST['url'];
            if($obs->valid($website)) {
             $obs->rfivulnerable($website);
            }
            else {
             echo "<span style=\"color: red;\">". htmlentities($website) ." is not a valid website.</span>";
            }
      }
      ?>
   </body>
</html>