CVE-2021-45971: Insyde INSYDEH2O

High severity, CVSS 8.2. EPSS: 0.3% chance of exploitation in the next 30 days.

An issue was discovered in SdHostDriver in Insyde InsydeH2O with kernel 5.1 before 05.16.25, 5.2 before 05.26.25, 5.3 before 05.35.25, 5.4 before 05.43.25, and 5.5 before 05.51.25. A vulnerability exists in the SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer (CommBufferData).

Affected products

• Insyde INSYDEH2O: from 5.1, before 5.16.25 (fixed in 5.16.25); from 5.2, before 5.26.25 (fixed in 5.26.25); from 5.3, before 5.35.25 (fixed in 5.35.25); from 5.4, before 5.43.25 (fixed in 5.43.25); from 5.5, before 05.51.25 (fixed in 05.51.25)

Published 2022-01-06. Last modified 2026-08-11.