❓ Help & Documentation

How it works

NetWatch executes system commands on the server to perform network diagnostics:

Ping Tool: Runs ping -c 2 [host] — Your input is appended directly to the command
DNS Lookup: Runs nslookup [domain]
Config Reader: API at /api/config?file=[path] — Reads any file on the system

Challenge Objective

The flag is stored in /flag.txt on the server. Your goal is to read it.

Hints

Hint 1: The ping tool takes your input and passes it directly to the system shell. What happens if you add extra commands after the hostname?
Hint 2: In a shell, the semicolon ; separates multiple commands. For example: echo hello; echo world
Hint 3: Try typing 127.0.0.1; cat /flag.txt in the ping tool.
Hint 4: Alternatively, the Config Reader API at /api/config?file=/flag.txt can read any file directly!

Learning Resources

This challenge teaches about:

Command Injection (CWE-78): When user input is passed to system commands without sanitization
Arbitrary File Read (CWE-22): When an API reads files based on user-supplied paths without restriction