An issue was discovered in Kernel 5.x in Insyde InsydeH2O, affecting HddPassword. Software SMI services that use the Communicate() function of the EFI_SMM_COMMUNICATION_PROTOCOL do not check whether the address of the buffer is valid, which allows use of SMRAM, MMIO, or OS kernel addresses.

A vulnerability exists in System Management Interrupt (SWSMI) handler of InsydeH2O UEFI Firmware code located in SWSMI handler that dereferences gRT (EFI_RUNTIME_SERVICES) pointer to call a GetVariable service, which is located outside of SMRAM. This can result in code execution in SMM (escalating privilege from ring 0 to ring -2).

A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer(QWORD values for CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.

In the kernel in Insyde InsydeH2O 5.x, certain SMM drivers did not correctly validate the CommBuffer and CommBufferSize parameters, allowing callers to corrupt either the firmware or the OS memory. The fixed versions for this issue in the AhciBusDxe, IdeBusDxe, NvmExpressDxe, SdHostDriverDxe, and SdMmcDeviceDxe drivers are 05.16.25, 05.26.25, 05.35.25, 05.43.25, and 05.51.25 (for Kernel 5.1 through 5.5).

Race condition in a subsystem in the Intel(R) LMS versions before 2039.1.0.0 may allow a privileged user to potentially enable escalation of privilege via local access.

Improper buffer restrictions in a subsystem in the Intel(R) CSME versions before 11.8.86, 11.12.86, 11.22.86, 12.0.81, 13.0.47, 13.30.17, 14.1.53, 14.5.32 and 15.0.22 may allow a privileged user to potentially enable escalation of privilege via local access.

Race condition in the firmware for some Intel(R) Processors may allow a privileged user to potentially enable escalation of privilege via local access.

Improper initialization in a subsystem in the Intel(R) CSME versions before 11.8.86, 11.12.86, 11.22.86, 12.0.81, 13.0.47, 13.30.17, 14.1.53, 14.5.32, 13.50.11 and 15.0.22 may allow a privileged user to potentially enable information disclosure via local access.

Improper initialization in the firmware for some Intel(R) Processors may allow a privileged user to potentially enable escalation of privilege via local access.

Insufficient control flow management in subsystem for Intel(R) CSME versions before 11.8.80, 11.12.80, 11.22.80, 12.0.70, 13.0.40, 13.30.10, 14.0.45 and 14.5.25 , Intel(R) TXE versions before 3.1.80 and 4.0.30 may allow an unauthenticated user to potentially enable escalation of privilege via physical access.

Improper isolation of shared resources in some Intel(R) Processors may allow an authenticated user to potentially enable information disclosure via local access.

Incomplete cleanup from specific special register read operations in some Intel(R) Processors may allow an authenticated user to potentially enable information disclosure via local access.

Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addresses of all prior memory writes are known may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka Speculative Store Bypass (SSB), Variant 4.