[https://crcksec.blogspot.com/2020/10/syskron-ctf-2020-beginner-writeup.html#bash_his](https://crcksec.blogspot.com/2020/10/syskron-ctf-2020-beginner-writeup.html#bash_his)

Original writeup (https://crcksec.blogspot.com/2020/10/syskron-ctf-2020-beginner-writeup.html#bash_his).