Finally! What a journey.
I’m curious with how others have gained foothold. I didn’t set up a similar environment as the box. Hope to share thinking processes and paths taken with others via PM.
Foothold
You probably found something interesting but cannot get RCE. Halt the exploit a step at a time to see where it is being sent.
User
You have powers to change something important to others without any prior knowledge. Noisy PE-aS can help you.
Root
Find something with special powers. You can look inside and Trace what it does. Look carefully and then literally get in its WAY.
This is no means an easy box! The sooner you realise this, the less you will feel deflated when you go through each stage. Don’t give up. PM me if you need some nudges.