Driver

Reading Time: 2 min read

#CVE-2021-1675#PrintNightmare#SCF-file-attack

Start 08:38 24-09-2025

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Scope:
10.10.11.106

Recon

Nmap

sudo nmap -sV -sC -sT -p- driver.htb -T5 --min-rate=5000 -vvvv -Pn

PORT     STATE SERVICE      REASON  VERSION
80/tcp   open  http         syn-ack Microsoft IIS httpd 10.0
| http-auth:
| HTTP/1.1 401 Unauthorized\x0D
|_  Basic realm=MFP Firmware Update Center. Please enter password for admin
|_http-server-header: Microsoft-IIS/10.0
| http-methods:
|   Supported Methods: OPTIONS TRACE GET HEAD POST
|_  Potentially risky methods: TRACE
|_http-title: Site doesnt have a title (text/html; charset=UTF-8).
135/tcp  open  msrpc        syn-ack Microsoft Windows RPC
445/tcp  open  microsoft-ds syn-ack Microsoft Windows 7 - 10 microsoft-ds (workgroup: WORKGROUP)
5985/tcp open  http         syn-ack Microsoft HTTPAPI httpd 2.0 (SSDP/UPnP)
|_http-server-header: Microsoft-HTTPAPI/2.0
|_http-title: Not Found
Service Info: Host: DRIVER; OS: Windows; CPE: cpe:/o:microsoft:windows

Host script results:
| smb2-security-mode:
|   3:1:1:
|_    Message signing enabled but not required
| smb-security-mode:
|   account_used: guest
|   authentication_level: user
|   challenge_response: supported
|_  message_signing: disabled (dangerous, but default)

From the nmap scan it seems like there’s an account on port 80 called admin.

80/TCP - HTTP

It seems like we’re dealing with HTTP Basic Authentication. Since we already know the username we will only need to identify the password.

Using hydra I can quickly find out the credential combination:

Logging in brings me to the following page:

Clicking on Firmware Updates shows us this page:

I tried uploading a webshell.php:

The URL told us that it worked:

However I wasn’t able to access the webshell since I didn’t know where it got uploaded, burp didn’t tell me either so there’s probably a different route here.

445/TCP - SMB

I wasn’t able to create a NULL session here, but this port is still open.

I started digging around when I found the following:

We can upload this file to the smb share through the webserver, and catch the hashes through responder.

PoC

By running sudo responder -I tun0 I then catch the hash for tony:

By using john we can easily crack the password.

tony
liltony

Foothold

5985/TCP - WinRM

Using the previously found creds we get easy access.

user.txt

Here we can get the user.txt right away:

Enumeration

After scrolling through it I found a scheduled task:

Before diving deeper into those files I enumerated further:

The above tells us that the Spooler service is running. We can use PrintNightmare.ps1 to easily get admin rights.

Privilege Escalation

CVE-2021-1675 - PrintNightmare

I downloaded over the script and added the tester user as follows:

I can now easily log in as this user:

root.txt

Cleaning Up

As part of the clean up we can now delete all files from the system and delete the created user:

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Finished 10:10 24-09-2025