PrintNightmare

WINDOWS PRINTER DRIVER

Here’s a fun rundown of a zero day vulnerability that was seen last year. It was called PrintNightmare, and it ravaged through some Windows computers. It used two CVEs that first grabbed credentials through SMB, and second allowed privilege escalation through the printer spool. I was able to play with this through a practice computer found on Hack The Box but can’t reveal its name due to it still being an active challenge (against the rules). In any case, seeing the exploit in action below should give you a good idea of the exploit’s capabilities.

RESOURCE FOR SMB SHARE SCF

Excerpt from this site:

When the user will browse the share a connection will established automatically from his system to the UNC path that is contained inside the SCF file. Windows will try to authenticate to that share with the username and the password of the user. During that authentication process a random 8 byte challenge key is sent from the server to the client and the hashed NTLM/LANMAN password is encrypted again with this challenge key. Responder will capture the NTLMv2 hash.

With basic credentials, this .scf file can be used to initiate a flow of viewable information. Before uploading, make a responder available to receive the information.

Bastard on HTB – Retired

BASTARD – HTB

RETIRED

NMAP

Nmap 7.91 scan initiated Fri Feb 12 23:36:02 2021 as: nmap -A -p- -T4 -oG nmap.init 10.129.29.109
Host: 10.129.29.109 () Status: Up
Host: 10.129.29.109 ()
Ports:
80/open/tcp//http//Microsoft IIS httpd 7.5/,
135/open/tcp//msrpc//Microsoft Windows RPC/,
49154/open/tcp//msrpc//Microsoft Windows RPC/
Ignored State: filtered (65532)
Nmap done at Fri Feb 12 23:38:42 2021 — 1 IP address (1 host up) scanned in 160.81 seconds

HTB – Bank – FH: DNS / File Upload

The Bank box was the first time I ran into virtual hosts on a web server. Till now, I’ve been able to discover all of the directories with a simple dirb or gobuster scan… this time was very different.

The NMAP scan showed only a few ports open. 22, 53, and 80. I always bypass 22 because there are rarely SSH exploits that go quick, so it was on to the other two ports. Interestingly, they had DNS running on port 53 and the description was ICS BIND. Bind is the Berkeley Internet Name Domain, and ISC bind can run in a large number of Linux environments. In this case, it was used to map to folders that didn’t show on an IP address scan of the machine.

HTB – Haircut – FH: Curl

The only ports available on the Haircut box were 22, and 80. As SSH usually reveals no interesting attack vectors, it’s always best to go for port 80. So I visited the site.

HTB – Sneaky – FH: SQLI

Foot-hold: SQL Injection

This box is going to make me do some learning! It was extremely basic in the scans, and didn’t reveal hardly anything. NMAP only showed port 80, and gobuster showed a folder called /dev. Those were two things that could easily be put together to give a hint as to the way forward.

HTB – October – FH: File Upload

Foot-hold: File upload after logging in

On October, only ports 22 and 80 were open. It was pretty obvious to go check on the website to see what was up.

HTB – Cronos – FH: DNS, then SQL Injection

Foot-hold: DNS, then SQL Injection

NMAP shoed a few ports for http, DNS, and SSH.
I wanted to go ahead and check for any exploits for Apache. Turns out that a lot of these Hack The Box ‘boxes’ run the same Apache. So I’ve seen this dance before. I can confirm that I can GET, POST, etc to the Apache server… but I haven’t been able to exploit this so far. The google search for Apache 2.4.18 revealed an attack called Optionsblee that I’ve seen before.

KALI

PrintNightmare

WINDOWS PRINTER DRIVER

Bastard on HTB – Retired

BASTARD – HTB

RETIRED

NMAP

HTB – Bank – FH: DNS / File Upload

HTB – Haircut – FH: Curl

HTB – Sneaky – FH: SQLI

HTB – October – FH: File Upload

HTB – Cronos – FH: DNS, then SQL Injection

HTB – Arctic – FH: Metasploit

HTB – Bastard – FH: Drupalgeddon2

HTB – Optimum – FH: RCE

HOME

OSCP References

NOTES & STRATEGIES

TECHNIQUES

THE BASICS

LINUX

LISTENING / GATHERING

BUFFER OVERFLOWS

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