This is a simple example payload for CVE-2022-21894 that demonstrates how an attacker could map a second stage payload in order to be able to call EFI services.
A writeup of this vulnerability can be viewed here: https://github.com/Wack0/CVE-2022-21894.
The code in this repository extends the PoC (poc_amd64_19041) of the repository mentioned above.