Writeup BreizhCTF 2022 - Faible Ty Reseau

Description:

# Faible Ty Reseau

    Value: 424

    Description:

    Voici un petit routeur fait maison ! Trouverez-vous le moyen d'obtenir le flag ?

 challenges.ctf.bzh:26002

Auteur: iHuggsy

Format : BZHCTF{}

Files:

file

Exploration

Let's be straithforward, and see what we got by connecting to the remote endpoint:
interface

Ok. It seems complicated at first, we need to see how the configuration testing behaves when we change the connexion parameters:
testing_configuration

Great! It make a ping -c 4 51.83.74.154 with 51.83.74.154 being the host parameter we provided. The hostname option don't seems to be of any use.

Exploitation

So, what if we try a little command injection to execute another command after the ping:
command_injection

Yes, we have Remote Command Execution!

Now, the last thing we need to do is to leak the content of "flag.txt" we just found.

flag_ty

Flag: BZHCTF{9024b719d4449bc9827478e50f0279427ccb542cc3ecdec21fce38c52b29561c}