Welcome to BrunnerCTF 2025
A CTF (Capture The Flag) is a cybersecurity competition with challenges in areas like web exploitation, pwn, reverse engineering, cryptography, digital forensics, boot2root, and more.
Each challenge hides a flag in the format brunner{something}, often in 1337. Submit flags to earn points.
Shake & Bake
You are currently in Shake & Bake - beginner-friendly challenges worth 10-50 points each. These challenges are tagged with the actual category.
If you get stuck with a Shake & Bake challenge, you can request hints on Discord via a help ticket - but force yourself to really "try harder" first (also, nobody stops you from using AI, but maybe try without it first to challenge yourself and learn something new). No hints will be provided for other challenges.
Dynamic Scoring
All other challenges are scored dynamically: the more solves a challenge has, the less it is worth for everyone who has solved it. Due to this, you might see your score decrease during the CTF.
Challenges start at a 1000 points and gradually decrease in score. After 75 solves, they reach a minimum of 100 points.
Instanced Challenges
Some challenges only have a downloadable handout file. Others require you to connect to a website or server. Most of these have a "Start Challenge" button that starts your team's instance of that challenge. Only your team has access to this instance.
Let's Go!
Before you move on, please read the rules of the CTF carefully. They contain important notes on what you're allowed to and not.
Then, submit the following flag:
brunner{n0w-y0u-kn0w-y0ur-C-T-F}
The flag is provided in the problem description.