$$ \text {An iCSI CTF (RED19)} $$

Setup:

• The VM needed for this challenge can be downloaded here.
• You’ll need Kali Linux as well.
• We’ll also use a Ubuntu machine you control for demonstration purposes.
• The final flag for this machine will be found in the same directory as action.php. (It has a long, complex file name)

First Steps:

• You will not have the login credentials to the machine.

• Before you power it on, go to the machine settings and give the network adapter a custom MAC address.

  • This way you will be able to locate it with the arp-scan utility within Kali.
  • Don’t use the MAC address I have below. Everyone in the class needs something different.
    • Manually randomize the MAC Address you give your machine!

  

Once you have started the CTF machine, launch a root shell in Kali and do the following:

• use the *arp-scan* utility to scan the entire subnet and report back on MAC addresses that are present.
  • Your Kali Linux machine must be on the same subnet as the CTF machine.
• Use grep to filter for the MAC address that you gave the CTF Machine.
• NOTE: I only grep for the OUI of the MAC address. You should grep for the entire MAC Address!
  • Use all 6 Hex characters in your grep

Start with an Nmap:

We see that this PHP server is running on port 8000 and we also see a convenient title of ‘PHP LFI!’

Open up the webpage and test for LFI to see if we can read the /etc/passwd file.