CVE-2022-33906

Severity: medium (CVSS 6.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-11-15 · updated 2026-06-17
Weakness: CWE-367

Description

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; from 5.3 before 5.3.05.36.23; from 5.4 before 5.4.05.44.23; from 5.5 before 5.5.05.52.23 — fixed in 5.2.05.27.23, 5.3.05.36.23, 5.4.05.44.23, 5.5.05.52.23

How to fix

Upgrade to a fixed version: Insyde Kernel 5.2.05.27.23, 5.3.05.36.23, 5.4.05.44.23, 5.5.05.52.23. Check the vendor advisory for mitigations.

References

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