[https://infosec.rm-it.de/2019/04/15/wpictf-2019-linux-category/#2](https://infosec.rm-it.de/2019/04/15/wpictf-2019-linux-category/#2)

Original writeup (https://infosec.rm-it.de/2019/04/15/wpictf-2019-linux-category/#2).