Got User. I really liked the BOF part (easy if you speak x64 assembly and know a thing or two about gdb, ROP, and ASRL), don’t know why there’s so much hate in the reviews. Made use of two functions plus a rop gadget plus SometHing else and… voila! Now on the way to root.
Tip: You’d better stay away from bitterman, write4, etc. Everything you need is in the binary.