Socket Challenges

Socket-based CTF challenges are all about interacting with a remote service. You're given an IP address and port. When you connect - usually with nc (netcat) - you’re met with a puzzle, a prompt, or just silence. Your job is to figure out what the service expects, send the right input, and earn the flag.

Most challenges follow a pattern: connect, receive a problem (like math, decoding, or trivia), respond correctly, and repeat. Some run through 50 rounds, others just need one good answer. You’ll often need to script your solution to keep up, especially if the problems are time-sensitive or follow a strict input format.

Watch for clues in the interaction: newlines (\n), specific byte counts, or delimiter characters tell you how to format your response. If you’re lucky, the challenge will include source code - read it! Knowing exactly what the service expects turns guesswork into certainty.

In short: connect with nc, pay attention, automate when needed, and don’t flood the wire. The box is speaking—listen closely.