Basic Capture the Flag Challenge 🚩

This is a quick and easy capture the flag challenge with the ability to root the box without the need for additional pen-testing tools.

Quick Start

• Create a new ubuntu ec2 instance on AWS (other cloud providers are available)
• SSH into the box and clone or copy the /website directory under the default user
  • scp -i <rsa_key> -r website ubuntu@<ec2-ip-dns>:/home/ubuntu/website
• Create a hugo's user on the box with a random hash password (make sure to save this for later)
  • sudo adduser hugo
• Enable ssh password authentication:
  • sudo nano /etc/ssh/sshd_config
  • change the line PasswordAuthentication no to PasswordAuthentication yes
  • change the line PermitRootLogin no to PermitRootLogin yes
  • Save the file and run:
  • sudo service ssh restart
• Log out as the ubuntu user and log back in as hugo
• Set hugo's account flag in the home directory:
  • echo <FLAG> > flag.txt
• Create a new directory for hugo's calculator app
• Copy the progress_notes.txt file across into this directory and fill it out with a public calculator repo
• In the calculator repo folder, generate an ssh key without a passphrase:
  • ssh-keygen -t rsa -m PEM
• Commit this to the repo and then revert the commit
• Log out and back into the default user and add this public key to the authorized keys for the root user
  • sudo echo "paste your key in here" >> /root/.ssh/authorized_keys