CVE-2022-32477

Privilege escalation via shared-buffer TOCTOU race

Published Feb 15, 2023 · Updated May 5, 2025

A TOCTOU race in InsydeH2O kernels 5.0 through 5.5 allows local users to corrupt SMRAM and escalate privileges via DMA. FvbServicesRuntimeDxe validates a command buffer in ACPI runtime memory that remains shared between SMM and non-SMM code, allowing its contents to change between validation and use. Exploitation requires local high privileges and DMA access; successful races cross the SMM trust boundary and can compromise firmware-protected memory.

CVSS severity8.2
High
EPSS probability0.13%
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 kernels 5.0 through 5.5 allows local users to corrupt SMRAM and escalate privileges via DMA. FvbServicesRuntimeDxe validates a command buffer in ACPI runtime memory that remains shared between SMM and non-SMM code, allowing its contents to change between validation and use. Exploitation requires local high privileges and DMA access; successful races cross the SMM trust boundary and can compromise firmware-protected memory.

The record

CVE
CVE-2022-32477
Published
Feb 15, 2023
Updated
May 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-367, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Feb 15, 2023CVE publishedPublication date reported by the CVE source.
  2. May 5, 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

8.2Insyde SoftwareCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
7.0NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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