CVE-2022-36338Public exploit

SMM code execution via hijacked GetVariable pointer

Published Sep 23, 2022 · Updated May 5, 2025

SMM callout in InsydeH2O kernel 5.0 through 5.5 allows local users with high privileges to execute arbitrary code in System Management Mode. FwBlockServiceSmm calls the UEFI GetVariable service through a replaceable pointer, allowing malware to hijack execution when a software SMI is generated. High local privileges and software-SMI access are required; successful exploitation gains execution in SMM beyond operating-system controls.

CVSS severity7.5
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SMM callout in InsydeH2O kernel 5.0 through 5.5 allows local users with high privileges to execute arbitrary code in System Management Mode. FwBlockServiceSmm calls the UEFI GetVariable service through a replaceable pointer, allowing malware to hijack execution when a software SMI is generated. High local privileges and software-SMI access are required; successful exploitation gains execution in SMM beyond operating-system controls.

The record

CVE
CVE-2022-36338
Published
Sep 23, 2022
Updated
May 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 23, 2022CVE 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

8.2NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
8.2CISA-ADPCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/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

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 exploitPublished

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

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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