ALLES CTF 2021: Nostego

Unfortunately infrastructure problems meant this CTF was quite frustrating to play. I spent most of my time refreshing a website waiting for my session to connect so I only solved two challenges before moving on to GrabCON. Anyway I solved Nostego first so here’s my solution. I believe my solution is pretty wrong but it worked so /shrug.

GrabCON 2021: Unknown 2

Fun CTF with quite a lot of variety in the challenges. I spent a bit of time on the binary reversing and pwning challenges this time because they seemed quite solvable for my basic skills. This is the 2nd in the “unknown” series.

FwordCTF 2021: BF

Good CTF this one that maybe I should have spent more time on but I was distracted with Wormcon and YauzaCTF on at the same time and building a SIFT box for disk forensics which turned out to be a huge time sink. Anyway on to the writeup!

Wormcon 0x01: Firm 1,2,3

Busy weekend with three simultaneous CTFs. I finished 19th over on this one so I feel like I should probably do at least one writeup. This is an unusual category for me, Internet of Things (IOT) which is a lot about firmware reverse engineering usually. Here’s the three challenges I solved Firm1, Firm2, and Firm3 as they’re all related.

corCTF 2021: 4096

An RSA challenge which are always my favourite in CTFs. This one was a combination of a few simple tricks. Below is my solution.