Bypass of GRUB lockdown restriction in Secure Boot mode via serial command MMIO base address

{
                    "vendor": "GNU",
                    "product": "grub2",
                    "versions": [
                        {
                            "status": "affected",
                            "version": "2.12",
                            "lessThan": "2.16",
                            "versionType": "semver"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }