Insyde Security Advisory 2022022

Insyde ID Advisory Category Impact of Vulnerability Severity Rating Original Date Last Revised
INSYDE-SA-2022022 Software AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H 8.2 02/01/2022 02/01/2022


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(CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.

Vulnerability Details


This corresponds fo CVE-2021-33627. It affects the driver FwBlockServiceSmm. This issue was discovered by Insyde engineering during an internal security review and reported on 25 May 2021. It was independently reported by Binarly (BRLY-2021-011) in September 2021. It was fixed in the following Insyde kernel versions. Kernel 5.0: 05.08.29. Kernel 5.1: 05.16.29. Kernel 5.2: 05.26.29. Kernel 5.3: 05.35.29. Kernel 5.4: Unaffected. Kernel 5.5: Unaffected.


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

Revision History:

Revision Date Description
1.0 02/01/2022 Initial Release
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