What’s a net cat? PicoCTF Challenge Writeup

Challenge Overview

Initial Analysis

The first step in any CTF challenge is to understand its core concept. Here’s how we can approach the initial analysis for this challenge:

Keywords and Hints: The challenge title mentions “netcat” or “nc,” strongly suggesting it involves using the netcat utility. If you’re unfamiliar with netcat, PicoCTF helpfully provides an nc tutorial cheat sheet for reference.

Understanding Netcat: Netcat (often abbreviated as nc) is a versatile command-line tool used for creating network connections using TCP or UDP protocols. It allows you to read data from and write data to network connections.

PROCEDURE

1 Understanding netcat functionalities

Open a terminal or command prompt window. To verify the available netcat commands and options, enter:

nc -h or netcat -h

Ouput of netcat -h command

This will display a help message listing various netcat functionalities.

2. Connecting to the Server:

The help message likely includes a command format for connecting to a server. This format typically involves:

nc <host> -p <port number>

Here, <host> represents the server address (e.g., jupiter.challenges.picoctf.org) and <port number> specifies the port on which the server listens for connections (which is 64287).

Based on the information provided, try the following command:

$ nc jupiter.challenges.picoctf.org  64287

This command attempts to establish a connection with the server jupiter.challenges.picoctf.org on port 64287.

3. Interacting with the Server:

If the connection is successful, you might be presented with a picoCTF flag.

The flag is picoCTF{nEtCat_Mast3ry_284be8f7}