TryHackMe: OverlayFS — CVE-2021–3493 Walkthrough.

OverlayFS — CVE-2021–3493 Walkthrough

Task 1 :- What is OverlayFS?

I have a very rough overview of what OverlayFS is → No answer needed.

Task 2 :- CVE-2021–3493 — OverlayFS Exploit

Credentials for SSH
Username: overlay
Password: tryhackme123

Deploy the machine with the Start Machine button in this task and wait up to 2 minutes for the VM to boot. → No answer needed

SSH into the machine with the credentials provided in the task text. → No answer needed

# ssh overlay@MACHINE_IP
overlay@MACHINE_IP’s password:

Grab the source code for the exploit from SSD-Disclosure here and save it as exploit.c on the target machine. → No answer needed

Hint :- Perhaps the easiest way is copy/pasting the code into a text editor like Nano or Vim!

$ nano exploit.c

Compile the exploit with gcc. If you’re finding this difficult, a command is given in the hints. → No answer needed

Hint :- gcc -o exploit exploit.c

$ gcc -o exploit exploit.c

$ ./exploit

bash-4.4# id

bash-4.4# cd /root/

Run your compiled exploit, and get root!
What’s the flag in /root/?

bash-4.4# cat flag.txt

thm{********************************}

Note :- Always terminate the machine you deployed in this room.

Thanks for reading hope you guys like. Post your questions in the comment section below!