This is the Global BrunnerCTF competition, open to everyone. It has its own scoreboard and is the competition used for the global ranking and CTFtime.
If your team has at least one member who currently lives in Denmark as their permanent or primary place of residence and you want to compete for prizes, you must participate on the Danish platform.
Placement on this scoreboard does not qualify a team for Danish positional prizes. Being Danish or otherwise meeting the Danish eligibility requirements while playing here is not sufficient.
GO TO DANISH COMPETITION →CTF Rules
- DO NOT share flags or collaborate with other teams during the competition.
- DO NOT ask for or give help outside your team until the event has ended. This includes asking other teams that have already solved the challenge.
- DO NOT attack, harass, or interfere with other players in any way.
- DO NOT hoard flags or deliberately delay submissions ("sandbagging").
- DO NOT indiscriminately brute-force flags or event infrastructure. Some challenges require limited brute forcing, but broad automated enumeration against our infrastructure, such as with DirBuster, is not allowed unless explicitly stated. If in doubt, open a support ticket on Discord.
- DO NOT create multiple accounts or teams.
- DO NOT discriminate. We have a zero-tolerance policy for discrimination, including but not limited to discrimination based on politics, gender, race, or sexual orientation. Teams or users with discriminatory or political content in their names may be removed or hidden if deemed inappropriate.
- Keep a respectful tone on Discord at all times, both towards organizers and other players.
- Rule violations may result in disqualification. Infrastructure abuse or attempted attacks against event infrastructure will result in an immediate ban and may be reported to the relevant authorities.
- There is no team size limit.
- Admins have the final word.
AI Use
AI use is not prohibited in the Open competition, but the challenges are best enjoyed without it and we recommend challenging yourself instead.
Struggling with a difficult problem, figuring out what to try next, and eventually finding the breakthrough yourself is a big part of what makes CTFs fun and rewarding. You will get considerably more out of the CTF by doing the thinking, experimenting, and struggling yourself rather than offloading the solving process to an LLM.
The Danish competition has a separate and strict no-AI policy. If you intend to compete there, make sure to read the Danish AI policy before working on the challenges.
Information
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All flags are in the format
brunner{.*}. - Challenges use dynamic scoring, meaning their point value decreases with the number of solves. Onboarding challenges are scored statically.
- The Global and Danish competitions have separate scoreboards and separate dynamic scoring. Solves on one platform do not affect challenge values or rankings on the other.
- You are allowed to ask the organizers for hints for Onboarding challenges in a support ticket on Discord. No hints or information will be provided for any other challenges.
- After the event, you are encouraged to publish writeups and share solutions on our Discord.
Rules may be updated at any time by the BrunnerCTF crew.