CVE-2022-33907
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 · uneditedDMA transactions which are targeted at input buffers used for the software SMI handler used by the IdeBusDxe driver could cause SMRAM corruption through a TOCTOU attack... DMA transactions which are targeted at input buffers used for the software SMI handler used by the IdeBusDxe driver could cause SMRAM corruption through a TOCTOU attack. This issue was discovered by Insyde engineering based on the general description provided by Intel's iSTARE group. Fixed in kernel 5.2: 05.27.25, kernel 5.3: 05.36.25, kernel 5.4: 05.44.25 https://www.insyde.com/security-pledge/SA-2022049
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 confidenceDMA transactions targeted at input buffers used for the software SMI handler in the IdeBusDxe driver can corrupt SMRAM (System Management RAM) through a TOCTOU (Time-of-Check to Time-of-Use) attack. This allows attackers to potentially execute code in System Management Mode (SMM), which operates at the highest CPU privilege level, bypassing OS security controls.
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>= 5.2, < 5.2.05.27.25>= 5.3, < 5.3.05.36.25>= 5.4, < 5.4.05.44.25CVSS 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
- Local
- Complexity
- High
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:H/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 checksWork through these to decide whether this CVE applies to you.
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Identify Insyde Kernel versionAccess the system BIOS/UEFI setup and look for the firmware version or Insyde kernel version information, typically found under Advanced, Security, or System Information sections. Alternatively, use a tool like dmidecode (if available on the OS) or a firmware extraction tool to read the BIOS version string.Affected if The displayed version matches one of the following patterns: 5.2.x where x is less than 05.27.25; 5.3.x where x is less than 05.36.25; or 5.4.x where x is less than 05.44.25.
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Confirm IdeBusDxe driver presenceExtract or inspect the UEFI firmware image using a tool like UEFITool, AMI firmware tools, or the vendor's BIOS update package. Search for the 'IdeBusDxe' driver or module within the firmware volume.Affected if The IdeBusDxe driver is present in the firmware image.
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Verify DMA buffer configurationCheck the UEFI variable settings or firmware configuration for DMA-related settings. On Insyde-based systems, this may be visible in the BIOS under 'Advanced' -> 'Storage Configuration' or similar, or may require examining the firmware ACPI tables (DMAR table) and the IdeBusDxe driver configuration.Affected if DMA transactions to input buffers are enabled, which is the default configuration for the IdeBusDxe driver.
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Confirm SMM configurationExamine the system firmware ACPI tables (specifically SPCR, SSDT, or DSDT) and look for SMM (System Management Mode) configuration. Check if SMRAM regions are defined and accessible. On Insyde systems, this may require firmware analysis tools or accessing the BIOS 'Security' or 'CPU Configuration' settings.Affected if SMM and SMRAM are enabled on the system, which is the default configuration on most Insyde-based systems.
A system is affected if it runs Insyde Kernel versions 5.2.x below 05.27.25, 5.3.x below 05.36.25, or 5.4.x below 05.44.25, has the IdeBusDxe driver present, and has DMA and SMM enabled (default settings).
Generated from the published advisory. Verify against your own configuration.
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.
dbcve · scoped5.2.05.27.255.3.05.36.255.4.05.44.25
Update the Insyde kernel/firmware to version 05.27.25 (kernel 5.2), 05.36.25 (kernel 5.3), or 05.44.25 (kernel 5.4) or later to apply the fix for the IdeBusDxe driver vulnerability.
Insyde kernel 5.2: upgrade to 05.27.25 or later; kernel 5.3: upgrade to 05.36.25 or later; kernel 5.4: upgrade to 05.44.25 or later
- 1. Identify the current Insyde H2O kernel version by checking the UEFI/BIOS firmware version on the affected system
- 2. Navigate to the vendor (Siemens or Insyde) support portal and locate the firmware update corresponding to the specific kernel version (5.2, 5.3, or 5.4)
- 3. Download the firmware update that includes the security fix (version 05.27.25 or later for kernel 5.2; 05.36.25 or later for kernel 5.3; 05.44.25 or later for kernel 5.4)
- 4. Apply the firmware update through the vendor-recommended method (typically via UEFI flash utility, BIOS update tool, or vendor management console)
- 5. Verify the firmware was successfully updated and the system boots normally
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation8.0 h
- Implementation24.0 h
- Testing16.0 h
- Review / QA8.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2022-33907 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2022-33907 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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