A collection of CTF writeups and solutions.
A CTF (short for Capture the Flag Competition) is a gamified computer security competition where players solve information security-related challenges to gain points. Although these competitions don’t involve running around to capture a flag, the underlying concept is the same.
In security CTFs, challengers compete to find a flag (usually a long sequence of characters) using modern hacking techniques.
CTFs can be categorized into three main categories:
- Jeopardy-style CTFs: These are the most popular kind of CTFs which involve solving a set of tasks from varying categories such as web exploitation, reverse engineering, cryptography, etc.
- Attack-defence CTFs: These involve each team being given their own vulnerable server and services. To succeed, teams must find exploits in and attack their opponents’ networks while protecting their own.
- Mixed CTFs: These can vary in possible formats and are a mix of the Jeopardy-style and Attack-defence competitions.