QUIZ TIME! Just answer the questions. Pretty easy right?
Host: pwn-2021.duc.tf
Port: 31905
After connecting to the server, we are presented with several questions which we must solve in 30 seconds, involving simple addition, hexadecimal, URL encoding, base 64, ROT13 and binary. It becomes clear quickly that we must write a script to answer these questions instead, which I have linked here. Flag: DUCTF{you_aced_the_quiz!_have_a_gold_star_champion}