Chapter 2 CTF{Sanity}

Obedient Cat

The next couple challenges are sanity check challenges. These challenges serve to assure the player that they are accessing the competition correctly and the infrastructure is working.

By following the hints in this challenge, you can learn how to download challenge files into the webshell.

This file has a flag in plain sight (aka "in-the-clear").

A file named Flag was provided for download. Upon downloading and opening the file, I discovered that it was a plain-text (.txt) file containing the flag:

academy{s4n1ty_v3r1f13d_61ddac22}

Hints

The lab provided three hints to guide the flag discovery process:

Hint 1

Any hints about entering a command into the Terminal (such as the next one), will start with a '$'… everything after the dollar sign will be typed (or copy and pasted) into your Terminal.

Hint 2

To get the file accessible in your shell, enter the following in the Terminal prompt: $ wget and a link to the flag. The link can be copied from the details section.

Hint 3

$ man cat

Super SSH

Using a Secure Shell (SSH) is going to be pretty important. Can you ssh as ctf-player to xebec.cylabacademy.net at port 16830 to get the flag?

You'll also need the password fa1a82ad. If asked, accept the fingerprint with yes.

If your device doesn't have a shell, you can use: https://webshell.cylabacademy.org

If you're not sure what a shell is, check out our Primer: https://primer.cylabacademy.org/#_the_shell

SSH Connection

Connected to the CTF server using SSH with the specified port 16830. After accepting the server's host key and entering the password, the server displayed the flag.

Command:

ssh -p 16830 ctf-player@xebec.cylabacademy.net

Flag:

academy{s3cur3_c0nn3ct10n_fbd97b2a}

Learning: Learned how to connect to a remote server using SSH with a custom port.

The Flag is looks like

academy{s3cur3_c0nn3ct10n_fbd97b2a}

Hints

The lab provided four hints to guide the flag discovery process:

Hint 1

https://linux.die.net/man/1/ssh

Hint 2

Start your challenge instance to view this hint.

Hint 3

How could you specify the port?

Hint 4

Remember, passwords are hidden when typed into the shell

What's a net cat?

Netcat CTF Writeup

Connected to the challenge server using Netcat on port 30860. The server displayed a welcome message and revealed the flag.

Command:

nc chatelaine.cylabacademy.net 30860

Flag:

academy{nEtCat_Mast3ry_Ed4EE28A}

Learning: Learned how to interact with remote services using Netcat.

The Flag is looks like

academy{nEtCat_Mast3ry_Ed4EE28A}

Hints

The lab provided one hints to guide the flag discovery process:

Hint 1

nc tutorial