Finally rooted. Not an easy box at all tbh.
Foothold: Search fo public et that let obtain r s**** without setting up ll g*b e********t. Personally I had to to do some tricks to have stable working condition.
User: Know where you are and what is used below you. Google how to r*** u*** p*******. Go back where you started and retrieve useful stuf that let you have a stable foot in.
Root: This took me a while after using typical enum tool. Finally with a deeper look of the enumeration output and with a deeper look into thing the enumeration tool pointed you to, I followed the right PATH and manage to trick that thing in order do to something evil and gain root privileges.
Important note: struggled a lot for this box with HTB free servers, I had to switch several times for the foothold part, finally switching to AUS server ended my pains.
Thanks a lot for the box!