Time to step up the game. Keep in mind there is more than one way to solve it. Good luck.
Rules
Feel free to pwn the binary on Ubuntu 16.04 or 17.04. Extra credits if you pwn it on 17.04.
Don’t ask me for hints. Hints will only be given 1 month after the challenge’s release as long as there are still 0 solves and demand for a hint.
Don't post your exploit below (with or without the spoiler tags)! This will not help those who still struggle. If you do pwn the binary, make sure to pm me your exploit with an explanation, and once I evaluate it, I’ll post in the comment section that you successfully pwned it providing your alias.