capture the flag, hacking, web application security

PicoCTF 2017 – WorldChat

Another day, another challenge…

In today’s blog post we will be solving the “WorldChat” challenge from the PicoCTF.

Let’s get started!

Going to the challenge we see:
PicoCTF_WorldChat_1

OK so we need to find the flag inside of the WorldChat app. According to the description when connecting to this app there will be many people on the app besides us.

Let’s look at the hints to see if it will help us.

PicoCTF_WorldChat_2

We need to us the nc command (we’ve used this in another challenge) and use the grep command to filter output.

Let’s try it.

PicoCTF_WorldChat_3

Connecting to the server we see a bunch of chats from different people. I pressed Ctrl + C to stop it.

Let’s use the hints and use the grep command with the “|” (pipe) command.

PicoCTF_WorldChat_4

PicoCTF_WorldChat_5

PicoCTF_WorldChat_6

PicoCTF_WorldChat_7

PicoCTF_WorldChat_8

PicoCTF_WorldChat_9

PicoCTF_WorldChat_10

Press Ctrl + C to end the chat.

I have only captured screenshots of output that has the flag. Entering the flag into the input box we acquired 30 points.