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Insydeh2oApplication · Insyde

CVE-2023-39281

CRITICAL · 9.8 CVSS v3.1 Published 2023-11-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A stack buffer overflow vulnerability discovered in AsfSecureBootDxe in Insyde InsydeH2O with kernel 5.0 through 5.5 allows attackers to run arbitrary code execution during the DXE phase.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A stack buffer overflow vulnerability exists in the AsfSecureBootDxe driver within InsydeH2O UEFI firmware versions 5.0 through 5.5. The overflow occurs during the DXE (Driver Execution Environment) phase, which runs with high privileges early in the boot process, allowing attackers to achieve arbitrary code execution at the firmware level.

MitigationApply the vendor-provided BIOS/UEFI firmware update from Insyde or the system OEM. This is a critical infrastructure-level patch requiring careful deployment planning given the firmware update process risks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Insydeh2oApplication
Affected:= 05.45.24.0039= 05.44.45.0017= 05.44.34.0055= 05.53.28.0013= 05.45.38.0005= 05.53.23.0011= 05.53.23.0014= 05.53.22.0008= 05.44.30.0022= 05.43.06.0021= 05.42.37.0031

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the UEFI firmware version
    Run 'dmidecode -s bios-version' on Linux, check System Information on Windows, or access BIOS/UEFI setup (typically press F2/Delete at boot) and look at the BIOS/UEFI version field
    Affected if The version matches any of these: 05.45.24.0039, 05.44.45.0017, 05.44.34.0055, 05.53.28.0013, 05.45.38.0005, 05.53.23.0011, 05.53.23.0014, 05.53.22.0008, 05.44.30.0022, 05.43.06.0021, or 05.42.37.0031
  2. Confirm the firmware vendor is InsydeH2O
    Check the BIOS/UEFI vendor string via 'dmidecode -s bios-vendor' on Linux, or check the System Information panel on Windows
    Affected if The vendor is listed as Insyde, InsydeH2O, or a system OEM using InsydeH2O firmware (such as certain Acer, HP, Dell, or Lenovo models)
  3. Determine the firmware release date or revision
    Check the BIOS/UEFI release date via 'dmidecode -s bios-release-date' on Linux, or the BIOS revision in System Information on Windows. Also check the firmware revision string in UEFI setup under 'BIOS Version' or 'UEFI BIOS Version'
    Affected if The firmware falls within the InsydeH2O 5.0 to 5.5 family line (versions typically start with 05.xx) and matches one of the specific versions in step 1 or is a variant between 5.0 and 5.5 that contains the vulnerable AsfSecureBootDxe driver
  4. Verify the AsfSecureBootDxe driver presence
    On systems with UEFI shell or firmware debugging tools available, enumerate the DXE drivers loaded. The AsfSecureBootDxe driver handles ASF (Alert Standard Format) secure boot functionality. Without specialized firmware analysis tools, this driver is not directly visible from the operating system
    Affected if The system firmware includes the AsfSecureBootDxe driver (this is implicit if InsydeH2O 5.0-5.5 firmware is confirmed, as the driver is part of the affected firmware distribution)

You are affected if your system runs InsydeH2O UEFI firmware version 05.45.24.0039, 05.44.45.0017, 05.44.34.0055, 05.53.28.0013, 05.45.38.0005, 05.53.23.0011, 05.53.23.0014, 05.53.22.0008, 05.44.30.0022, 05.43.06.0021, or 05.42.37.0031, which contain the vulnerable AsfSecureBootDxe driver in the DXE phase.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-provided BIOS/UEFI firmware update from Insyde or the system OEM. This is a critical infrastructure-level patch requiring careful deployment planning given the firmware update process risks.

Fix this in Insydeh2o Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,080
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-39281 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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