CVE-2022-33906: Insyde Kernel

Medium severity, CVSS 6.4. EPSS: 0.2% chance of exploitation in the next 30 days.

DMA transactions which are targeted at input buffers used for the FwBlockServiceSmm software SMI handler could cause SMRAM corruption through a TOCTOU attack. DMA transactions which are targeted at input buffers used for the software SMI handler used by the FwBlockServiceSmm driver could cause SMRAM corruption through a TOCTOU attack. This issue was discovered by Insyde engineering based on the general description provided by Intel's iSTARE group. Fixed in kernel 5.2: 05.27.23, 5.3: 05.36.23, 5.4: 05.44.23, 5.5: 05.52.23 https://www.insyde.com/security-pledge/SA-2022048

Affected products

• Insyde Kernel: from 5.2, before 5.2.05.27.23 (fixed in 5.2.05.27.23); from 5.3, before 5.3.05.36.23 (fixed in 5.3.05.36.23); from 5.4, before 5.4.05.44.23 (fixed in 5.4.05.44.23); from 5.5, before 5.5.05.52.23 (fixed in 5.5.05.52.23)

Published 2022-11-15. Last modified 2026-06-17.