Insyde's Security Pledge

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.

CVSS Vector: AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CVE-2021-33626

This corresponds to CVE-2021-33626. It affects the driver SmmResourceCheckDxe. This issue was discovered by Insyde engineering during an internal security review of several Insyde drivers and entered as a security incident on May 28, 2021. It was independently reported by Binaryly (BRLY-2021-013) in September 2021.

It was fixed in the following Insyde kernel versions on June 1, 2021. Kernel 5.1: 05.16.23 Kernel 5.2: 05.26.23 Kernel 5.3: 05.35.23 Kernel 5.4: 05.43.23 Kernel 5.5: 05.51.23

Insyde Software would like to thank Binarly for reporting this issue.