CTF Writeup – plumbing – PicoCTF

CTF Writeup by Frigyes

Introduction

This challenge was originally featured on picoCTF 2019

Description: Sometimes you need to handle process data outside of a file. Can you find a way to keep the output from this program and search for the flag? Connect to address port

Solution

By connecting with netcat, we are greeted with a 10002 line output. The key is somewhere in there.

Output saved to a txt file

Now we could be lame and redirect the output to a file, and search it from GUI, but we are hardcore CLI users here, right? So I just piped the output to grep with the pipe character “|”, and looked for “picoCTF{” pattern:

An there we go, we have a flag!

picoCTF{digital_plumb3r_ea8bfec7}

If you liked this writeup, check out other writeups I wrote!

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