Finally rooted the machine. It was a fun box, learnt a lot from this box.
Thanks to all the people who gave nudges.
Anyone who is having trouble with transferring the file can read this article
Also don’t try for reverse shell because you will only waste your time doing so.
For initial foothold: backup and Exploit db has something for you. Look at the info to know what to avoid.
For user1: if you can dump then you can get inside
For user2: Stay home and read the files
For root: Look what he has changed.
PM if you need help