Read the full write-up at http://aukezwaan.nl/2016/10/03/h4ck1t-ctf-brazil-p13c3-0f-c4k3-100-points/

Original writeup (http://aukezwaan.nl/2016/10/03/h4ck1t-ctf-brazil-p13c3-0f-c4k3-100-points/).