典型的PHP代码审计开始审计^()[]{}$\,\x0A和\xFF以及不配对的单/双引号转义$sandbox=md5("glzjin".$_SERVER['REMOTE_ADDR']);echo'youareinsandbox'.$sandbox;@mkdir($sandbox);//新建目录，默认权限，最大可能的访问权chdir($sandbox);//改

<?phpif(isset($_SERVER['HTTP_X_FORWARDED_FOR'])){$_SERVER['REMOTE_ADDR']=$_SERVER['HTTP_X_FORWARDED_FOR'];}if(!isset($_GET['host'])){highlight_file(__FILE__);}else{$host=$_GET['