Ok, i’ve already spent more than 10 days onto this behemoth…getting user’s flag has been a gigantic learning experience (thanks also to @TazWake) , but i have to admit that root is out of my reach for now.
If anyone wants to give me one or more nudges, it’ll be more than welcome. for now the only thing that i can say is that maybe i have understood what to do, but i am almost completely illiterate onto this branch of exploitation…