[https://infosec.rm-it.de/2018/07/29/isitdtu-ctf-2018-friss/](https://infosec.rm-it.de/2018/07/29/isitdtu-ctf-2018-friss/)

Original writeup (https://infosec.rm-it.de/2018/07/29/isitdtu-ctf-2018-friss/).