Memory leak with format strings.

Post:
<https://github.com/jesux/ctf-write-ups/tree/master/nullcon-2018/exploiting1>

Code:
<https://github.com/jesux/ctf-write-ups/blob/master/nullcon-2018/exploiting1/nullcon2018-exp1.py>

Original writeup (https://github.com/jesux/ctf-write-ups/tree/master/nullcon-2018/exploiting1).