An issue was discovered in SystemFirmwareManagementRuntimeDxe in Insyde InsydeH2O with kernel 5.0 through 5.5. The implementation of the GetImage method retrieves the value of a runtime variable named GetImageProgress, and later uses this value as a function pointer. This variable is wiped out by the same module near the end of the function. By setting this UEFI variable from the OS to point into custom code, an attacker could achieve arbitrary code execution in the DXE phase, before several chipset locks are set.

An SMM memory corruption vulnerability in the SMM driver (SMRAM write) in CsmInt10HookSmm in Insyde InsydeH2O with kernel 5.0 through 5.5 allows attackers to send arbitrary data to SMM which could lead to privilege escalation.

An issue was discovered in IhisiServicesSmm in Insyde InsydeH2O with kernel 5.0 through 5.5. There are arbitrary calls to SetVariable with unsanitized arguments in the SMI handler.

An issue was discovered in TrEEConfigDriver in Insyde InsydeH2O with kernel 5.0 through 5.5. It can report false TPM PCR values, and thus mask malware activity. Devices use Platform Configuration Registers (PCRs) to record information about device and software configuration to ensure that the boot process is secure. (For example, Windows uses these PCR measurements to determine device health.) A vulnerable device can masquerade as a healthy device by extending arbitrary values into Platform Configuration Register (PCR) banks. This requires physical access to a target victim's device, or compromise of user credentials for a device. This issue is similar to CVE-2021-42299 (on Surface Pro devices).