📝 Task

You’re now an expert in TCP, which is great for reliable communication, but it’s also complex. This challenge introduces UDP (User Datagram Protocol) – a simpler, connectionless alternative to TCP.

Objective:
From your host at 10.0.0.1, send the message Hello, World! to the remote host at 10.0.0.2 on UDP port 31337.

✅ You can use either Python or netcat. The goal is to receive a response containing the flag.

📚 Background: What is UDP?

UDP is a lightweight protocol used when speed is preferred over reliability. Unlike TCP:

  • No handshake or session establishment
  • No packet ordering
  • No retransmission of lost packets
  • No connection state is kept

You just fire the packet and hope it arrives.

UDP is commonly used in:

  • DNS queries
  • Video/audio streaming
  • Online gaming

🚀 Solution (Netcat)

We use nc (netcat) in UDP mode with the -u flag:

nc -u 10.0.0.2 31337

Once connected, type:

Hello, World!

And you will receive the response:

Hello, World!
pwn.college{0zfudnc9yN64T-umRea3B0busUh.0lM0AjNxwSM0IzMyEzW}

Flag

pwn.college{0zfudnc9yN64T-umRea3B0busUh.0lM0AjNxwSM0IzMyEzW}