X-NUCA'2019部分题目WP

0x00 前言题目质量好高，题目好评0x01 Ezphp题目描述ezphp php for beginner.hint: no race condition题目解答题目环境：apache+php题目源码： $files = scandir('./'); foreach($files as $file) { if(is_file($file)){ if ($file !== "index.php") { unlink($file); } } } include_once("fl3g.php"); if(!isset($_GET['content']) || !isset($_GET['filename'])) { highlight_file(__FILE__); die(); } $content = $_GET['content']; if(stristr($content,'on') || stristr($content,'html') || stristr($content,'type') || stristr($content,'flag') || stristr($content,'upload') || stristr($content,'file')) { echo "Hacker"; die(); } $filename = $_GET['filename']; if(preg_match("/[^a-z\.]/", $filename) == 1) { echo "Hacker"; die(); } $fi ………………………………