***SPOILER***Walkthrough of the machine called "Fantastic" in the Offsec Proving Grounds...don't watch unless you want help getting through the machine.
Links used in walkthrough:
CVE-2021-43798: https://j0vsec.com/post/cve-2021-43798/
Grafana Decryptor: https://github.com/Sic4rio/Grafana-Decryptor-for-CVE-2021-43798
Disk membership privesc:
https://medium.com/@keyboardsamurai007/linux-privilege-escalation-through-group-exploitation-7227f0871022
https://steflan-security.com/linux-privilege-escalation-exploiting-user-groups/#disk