speeds and feeds

Problem

There is something on my shop network running at mercury.picoctf.net:16524, but I can't tell what it is. Can you?

Solution

1. We can use nc to connect to the challenge and output the commands to a file: nc mercury.picoctf.net 16524 > cnc_command.txt

2. Searching for What language does a CNC machine use? finds that the answer is g-code Searching for simulate g-code finds NCViewer (WebGCode is another option).

3. We can paste in the contents of cnc_command.txt into the "GCode File" panel and then click "Plot" to view the flag.

Flag

picoCTF{num3r1cal_c0ntr0l_1395ffad}