An issue was discovered in Insyde InsydeH2O with kernel 5.2 through 5.5. The Save State register is not checked before use. The IhisiSmm driver does not check the value of a save state register before use. Due to insufficient input validation, an attacker can corrupt SMRAM.

An issue was discovered in IhisiSmm in Insyde InsydeH2O with kernel 5.0 through 5.5. IHISI function 0x17 verifies that the output buffer lies within the command buffer but does not verify that output data does not go beyond the end of the command buffer. In particular, the GetFlashTable function is called directly on the Command Buffer before the DataSize is check, leading to possible circumstances where the data immediately following the command buffer could be destroyed before returning a buffer size error.

An issue was discovered in IhisiSmm in Insyde InsydeH2O with kernel 5.0 through 5.5. It is possible to write to an attacker-controlled address. An attacker could invoke an SMI handler with a malformed pointer in RCX that overlaps SMRAM, resulting in SMM memory corruption.

An issue was discovered in IhisiSmm in Insyde InsydeH2O with kernel 5.0 through 5.5. IHISI subfunction execution may corrupt SMRAM. An attacker can pass an address in the RCX save state register that overlaps SMRAM, thereby coercing an IHISI subfunction handler to overwrite private SMRAM.

An issue was discovered in ChipsetSvcSmm in Insyde InsydeH2O with kernel 5.0 through 5.5. There is insufficient input validation in BIOS Guard updates. An attacker can induce memory corruption in SMM by supplying malformed inputs to the BIOS Guard SMI handler.

An issue was discovered in IhisiSmm in Insyde InsydeH2O with kernel 5.0 through 5.5. A malicious host OS can invoke an Insyde SMI handler with malformed arguments, resulting in memory corruption in SMM.

An issue was discovered in Insyde InsydeH2O with kernel 5.0 through 5.5. DMA attacks on the FvbServicesRuntimeDxe shared buffer used by SMM and non-SMM code could cause TOCTOU race-condition issues that could lead to corruption of SMRAM and escalation of privileges. This attack can be mitigated using IOMMU protection for the ACPI runtime memory used for the command buffer. This attack can be mitigated by copying the firmware block services data to SMRAM before checking it.

An issue was discovered in Insyde InsydeH2O with kernel 5.0 through 5.5. DMA attacks on the VariableRuntimeDxe shared buffer used by SMM and non-SMM code could cause TOCTOU race-condition issues that could lead to corruption of SMRAM and escalation of privileges. This issue was fixed in the kernel, which also protected chipset and OEM chipset code.

An issue was discovered in Insyde InsydeH2O with kernel 5.0 through 5.5. DMA attacks on the PnpSmm shared buffer used by SMM and non-SMM code could cause TOCTOU race-condition issues that could lead to corruption of SMRAM and escalation of privileges. This attack can be mitigated using IOMMU protection for the ACPI runtime memory used for the command buffer. This attack can be mitigated by copying the firmware block services data to SMRAM before checking it.

An issue was discovered in Insyde InsydeH2O with kernel 5.0 through 5.5. DMA attacks on the SdHostDriver buffer used by SMM and non-SMM code could cause TOCTOU race-condition issues that could lead to corruption of SMRAM and escalation of privileges. This attack can be mitigated by using IOMMU protection for the ACPI runtime memory used for the command buffer. This attack can be mitigated by copying the link data to SMRAM before checking it and verifying that all pointers are within the buffer.