Crimson Defense CTF

Collegiate Level CTF

CDCTF 2025

Crimson Defense CTF 2025 will be held on Saturday, September 20th from 10am to 10pm Central Time!

This 12-hour competition is designed for collegiate-level CTF players, and all ability levels are welcome! CDCTF is a team competition, you may have up to FOUR participants per team. Universities may have multiple teams representing their school. There will be challenges of all difficulties representing the following categories: Reverse Engineering, Pwning, Network Traffic Analysis, Forensics, Web App Exploitation, Password Cracking, Cryptography, and Open Source Intelligence.

Looking for our middle/high school competition? Click here for info on UACTF 2026.

Stay tuned! CDCTF 2025 Registration will open in August 2025!

CDCTF Rules

  1. Attacking the CDCTF platform is strictly prohibited
  2. Sharing flags or solutions with other teams during the competition is strictly prohibited and may result in the revocation of Awards
  3. Recieving help from individuals NOT on your team is prohibited
  4. Brute-forcing is strictly prohibited
  5. Using automated tools against the CDCTF hosted challenges is prohibited unless specified
  6. Please do not sabotage other teams, create multiple accounts, use bots/scripts to automate submissions, or share competition materials with others not competing in CDCTF during the competition. Write-ups are encouraged, and may only be posted after the conclusion of the competition.

The tiebreaker for final points will be as follows: time of last correct submission minus time of qualifying flag submission. Submission accuracy is NOT considered for scoring, and flag-hoarding is discouraged.

Play fair! Any infractions to these rules may result in: point deductions, disqualification, or a permanent ban from the competition.

About CDCTF

CDCTF was created by CD Officers in 2023 to introduce CTF style competitions to new Crimson Defense members. The competition used challenges created by Crimson Defense members/alumni from the previous year's UACTF high school competition. In 2025, it was decided by the Crimson Defense Officers to open up the competition to any college student in the United States!

CDCTF 2025 will contain more advanced challenges than past CDCTFs, but there will still be beginner-friendly challenges available. The goal of CDCTF is to introduce new students to cyber, but also to give veteran students a chance to sharpen their skills for the new academic year!