CVE-2022-24351

Boot-process code execution via post-measurement FDM modification

Published Dec 16, 2023 · Updated Aug 3, 2024

TOCTOU in affected InsydeH2O Kernel 5.2 through 5.5 releases allows local users to redirect code execution during boot via SPI injection. FDM contents can be modified after measurement, causing the remaining boot process to consume altered data and code. Exploitation requires winning the post-measurement race; successful modification compromises boot-process integrity without reported disclosure or service interruption.

CVSS severity5.9
Medium
EPSS probability0.16%
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

TOCTOU in affected InsydeH2O Kernel 5.2 through 5.5 releases allows local users to redirect code execution during boot via SPI injection. FDM contents can be modified after measurement, causing the remaining boot process to consume altered data and code. Exploitation requires winning the post-measurement race; successful modification compromises boot-process integrity without reported disclosure or service interruption.

The record

CVE
CVE-2022-24351
Published
Dec 16, 2023
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-367, T1542.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 16, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.9Insyde SoftwareCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1542.001Pre-OS Boot: System Firmware

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

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