Flagvent 2025

24 days of CTF challenges 🎅

About

Flagvent is a CTF competition with 24 challenges that runs from December 1st to December 24th. A new challenge unlocks each day at 18:00 CET, advent calendar style!

Additionally, there's one hidden challenge per week hidden somewhere in any challenge. Keep your eyes peeled!

Join our Discord server to stay up to date.

Participate

We're currently accepting challenge submissions, just open a ticket on our Discord, if you'd like to become an author. We'll keep you updated on the available slots and categories.

Go to Challenge Platform

Schedule

Challenges will have a varying difficulty, which will peak in the middle and on weekends of the CTF. The difficulty slowly decreases towards the end so you have time for preparing to celebrate Christmas with your family:

Difficulty over time

Challenge Schedule

Mon Tue Wed Thu Fri Sat Sun
1
EASY
2
EASY
3
EASY
4
EASY
5
MEDIUM
6
MEDIUM
7
MEDIUM
8
HARD
9
HARD
10
HARD
11
HARD
12
LEET
13
LEET
14
HARD
15
HARD
16
HARD
17
MEDIUM
18
MEDIUM
19
LEET
20
MEDIUM
21
MEDIUM
22
EASY
23
EASY
24
EASY

Difficulties

  • EASY - 7 challenges
  • MEDIUM - 7 challenges
  • HARD - 7 challenges
  • LEET - 3 challenges

Categories

  • Fun
  • Web Exploitation
  • Binary Exploitation
  • Cryptography
  • Reverse Engineering
  • Linux
  • Miscellaneous

Rules

  • No DoS against the organizers infrastructure allowed
  • Limited bruteforce/scanning of challenge services is allowed.
  • Attacking the organizers infrastructure is forbidden.
  • Valid challenge targets are located at:
    • https://<UUID>.challs.flagvent.org:1337 (https)
    • <UUID>.challs.flagvent.org:31337 (tls)
  • Flag and/or hint sharing is discouraged
  • Use /solved <flag> on the discord to get access to a writeup channel for a challenge
  • Solves within 24h of a challenge release get 100 extra points awarded
  • Challenges initially are worth 500 points, the value of their flags decreases with the amount of solves
  • Challenge authors are not allowed to first blood their own challenges
  • LLM usage is discouraged. We know that ChatGPT can solve some challenges in 5 minutes, but can you?
  • Have fun!