22 lines (18 loc) · 492 Bytes

Challenge

<?php 
if ($_SERVER['HTTP_X_FORWARDED_FOR'] === '127.0.0.1') {

    echo "<br >Welcome My Admin ! <br >";

    $pattern = $_GET[pat];
    $replacement = $_GET[rep];
    $subject = $_GET[sub];

    if (isset($pattern) && isset($replacement) && isset($subject)) {
        preg_replace($pattern, $replacement, $subject);
    }else{
        die();
    }

}
?>

Refference

赛博地球杯工业互联网安全大赛工控云管理系统设备维护中心被植入后门