Lab Instructions

Overview

In each lab (every week), you are asked to solve a set of challenges (typically 10~15 challenges except for the first two weeks). In each challenge, you have to submit the flag for the challenge via the scoreboard.

A flag is an ASCII string that matches with a regular expression of cand{[^}]+}, and you can find it either in the challenge program or in the challenge directory (usually as a ‘flag’ file). Your job is to read this flag by exploiting the distributed challenges.

Taking actions #1 (Registration)

  1. Register your account

  • Visit the submission site: here. You will use the registration menu.

  1. Connect to SSH @ cand.unexploitable.systems.

  • Account creation request can be done via Discord by sending your preferred username and SSH public key to Yeongjin.

  1. Connect to the course server

[host] $ ssh YOURID@cand.unexploitable.systems

# let's start week2!
[CTF_server] $ fetch week2
[CTF server] $ cd week2
[CTF server] $ cd bof-level0
[CTF server] $ ./bof-level0

  1. Submit your solution and flag

# Submit Flag
  1) Visit the scoring website
     https://ctf.unexploitable.systems

  2) Choose the challenge name from the correct week-X set

  3) Submit the flag!