We were only given the website `http://chals5.umdctf.io:4002` and no other information.

The flag is hidden in `http://chals5.umdctf.io:4002/<number>`, where \<number\> is a number from 0 to 20. Each of the pages has a character, which corresponds to the character in the number's place in the flag.

I wrote a python script to extract the flag.

import requests

ans = ''

for i in range(21):
ans += r.text



The flag is UMDCTF-{r0b0t5_43v3r}.

Original writeup (https://github.com/keyboard-monkeys/ctf-writeups/blob/main/2021-UMDCTF/web_the_matrix_revolutions.md).