该题目涉及到了序列化；Base64解码；cgi；ssrf；php中的file协议；
代码审计，我只知道涉及到了序列化，还有我提交的方法是POST的，其他的我都不是很懂了，所以看了别人的wp；；
https://blog.csdn.net/qq_53460654/article/details/116329685
<?php
// php版本:5.4.44
header("Content-type: text/html; charset=utf-8");
highlight_file(__FILE__);
class evil{
public $hint;
public function __construct($hint){
$this->hint = $hint;
}
public function __destruct(){
if($this->hint==="hint.php")
@$this->hint = base64_encode(file_get_contents($this->hint));
var_dump($this->hint);
}
function __wakeup() {
if ($this->hint != "╭(●｀∀´●)╯") {
//There's a hint in ./hint.php
$this->hint = "╰(●’◡’●)╮";
}
}
}
class User
{
public $username;
public $password;
public function __construct($username, $password){
$this->username = $username;
$this->password = $password;
}
}
function write($data){
global $tmp;
$data = str_replace(chr(0).'*'.chr(0), '\0\0\0', $data);
$tmp = $data;
}
function read(){
global $tmp;
$data = $tmp;
$r = str_replace('\0\0\0', chr(0).'*'.chr(0), $data);
return $r;
}
$tmp = "test";
$username = $_POST['username'];
$password = $_POST['password'];
$a = serialize(new User($username, $password));
if(preg_match('/flag/is',$a))
die("NoNoNo!");
unserialize(read(write($a)));
