Thanks to @naveen1729 for helping me out of the rabbit hole
Nice box 
User
It is necessary to see what the developers have changed in the code of the application, it is possible to see something interesting. The part of the RCE is to see how to take advantage of the language and the part of getting out of jail was complicated, sometimes one relies on any script that is in the machine when you can modify it and see if it is returning what it should.
Root
The part of the root is simple, just copy and paste a part of “that” and get what you want according to the documentation