CVE-2022-36448Public exploit

SMM code execution via unchecked NVRAM address

Published Sep 28, 2022 · Updated May 21, 2025

SMM memory corruption in Insyde InsydeH2O kernel 5.4 and 5.5 allows local users with high privileges to execute code in SMM. The PnpSmm Software SMI handler trusts the address stored in the IhisiParamBuffer NVRAM variable and writes a predictable result at that address plus eight bytes. Ring 0 control is required; successful exploitation reaches ring -2 and can execute code in SMM, bypass firmware protections, or crash the system.

CVSS severity8.2
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

SMM memory corruption in Insyde InsydeH2O kernel 5.4 and 5.5 allows local users with high privileges to execute code in SMM. The PnpSmm Software SMI handler trusts the address stored in the IhisiParamBuffer NVRAM variable and writes a predictable result at that address plus eight bytes. Ring 0 control is required; successful exploitation reaches ring -2 and can execute code in SMM, bypass firmware protections, or crash the system.

The record

CVE
CVE-2022-36448
Published
Sep 28, 2022
Updated
May 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 28, 2022CVE publishedPublication date reported by the CVE source.
  2. May 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

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

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo