Design/Logic Flaw

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).