CVE-2022-31243

SMRAM corruption via DMA input-buffer race

Published Nov 14, 2022 · Updated Apr 30, 2025

A TOCTOU race in InsydeH2O's FvbServicesRuntimeDxe driver allows local users with high privileges to corrupt SMRAM through DMA. The SMI handler checks an input buffer and later uses it without preventing a DMA transaction from changing the buffer between those operations. Exploitation requires local high-privilege access and a successful race; the resulting write corrupts protected memory used by system-management firmware.

CVSS severity7.5
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A TOCTOU race in InsydeH2O's FvbServicesRuntimeDxe driver allows local users with high privileges to corrupt SMRAM through DMA. The SMI handler checks an input buffer and later uses it without preventing a DMA transaction from changing the buffer between those operations. Exploitation requires local high-privilege access and a successful race; the resulting write corrupts protected memory used by system-management firmware.

The record

CVE
CVE-2022-31243
Published
Nov 14, 2022
Updated
Apr 30, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-367
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Nov 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.4CISA-ADPCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
7.5Insyde SoftwareCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
6.4NIST NVDCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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