BruCON 2023 CTF Many challenges, many flags in this CTF. Our team happily ranked 6th / 64. Positive aspects: It is really interesting to have a full document with network and architecture diagrams of what looks like a real beer brewery. It makes the challenges feel real and I appreciated the time the organizers took to prepare such a scenario I enjoyed the PLC challenges where we used and hacked into real PLCs.

This is a write-up for some of the PLC / Critical Infrastructure challenges of BruCON. PLC: The Secret Ingredient This is an OT challenge where we interact with a real PLC. We are asked to “get the PLC program and rescue the company secret located in datablock 23”. The IP address of the PLC is 35.232.66.239:102. I solved this one with a team mate, and he did the most difficult part.

Crypto: Dragon’s Crib Our team spent considerable time on this challenge, which only provided 50 points in the end. True, it was easier than I had expected, but still I think it deserved more points. We are provided with an encryption algorithm, implemented in Python, and 5 ciphertexts: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 import binascii import random import sys SEED = random.