CVE-2022-32470
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 · uneditedAn issue was discovered in Insyde InsydeH2O with kernel 5.0 through 5.5. DMA attacks on the FwBlockServiceSmm shared buffer used by SMM and non-SMM code could cause TOCTOU race-condition issues that could lead to corruption of SMRAM and escalation of privileges. This attack can be mitigated using IOMMU protection for the ACPI runtime memory used for the command buffer. This attack can be mitigated by copying the firmware block services data to SMRAM before checking it.
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 confidenceInsydeH2O UEFI firmware versions 5.0-5.5 contain a TOCTOU race condition in the FwBlockServiceSmm component. DMA attacks on the shared buffer between SMM and non-SMM code can corrupt SMRAM and escalate privileges to SMM level.
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>= 5.0, < 5.2.05.27.27>= 5.3, < 5.3.05.36.27>= 5.4, < 5.4.05.44.27>= 5.5, < 5.5.05.52.27CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:L/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 if the system uses InsydeH2O UEFI firmwareRun 'dmidecode -s bios-vendor' and 'dmidecode -s bios-version' to retrieve the BIOS vendor and version information. Alternatively, use 'uefi-firmware-viewer' or 'Chipsec' to extract and inspect the UEFI firmware ROM.Affected if The vendor is not Insyde or the BIOS version does not start with a 5.x series (indicating it may be an unaffected firmware line)
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Compare the installed firmware version to the affected version rangesMatch the version from step 1 against these ranges: 5.0 to 5.2.05.27.26, 5.3 to 5.3.05.36.26, 5.4 to 5.4.05.44.26, or 5.5 to 5.5.05.52.26. Extract the full version string from the firmware.Affected if The version falls within any of the four affected ranges (any version >= 5.0 and < 5.2.05.27.27, or >= 5.3 and < 5.3.05.36.27, or >= 5.4 and < 5.4.05.44.27, or >= 5.5 and < 5.5.05.52.27)
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Confirm the FwBlockServiceSmm SMM driver is present in the firmwareExtract the UEFI firmware ROM using tools like 'uefi-firmware-viewer', 'UEFITool', or 'Chipsec'. Search within the firmware image for the 'FwBlockServiceSmm' driver module (typically in the SMM core volume).Affected if The FwBlockServiceSmm driver is found in the firmware image, indicating the vulnerable component is loaded
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Check if IOMMU protection is enabled for ACPI runtime memoryBoot into the UEFI setup and navigate to advanced chipset or security settings. Verify whether IOMMU (also labeled as Intel VT-d or AMD-Vi) is enabled. Alternatively, run 'dmesg | grep -i iommu' on Linux to check runtime status.Affected if IOMMU is disabled or not available, meaning the mitigation is not present and DMA attacks are possible
The system is affected if it runs InsydeH2O firmware version 5.0-5.5 within the vulnerable ranges AND contains the FwBlockServiceSmm driver AND lacks IOMMU protection, allowing DMA-based SMRAM corruption.
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 · scoped5.2.05.27.275.3.05.36.275.4.05.44.27
Enable IOMMU protection for ACPI runtime memory used as the command buffer, or modify firmware to copy FwBlockServiceSmm data into SMRAM before performing validation checks.
5.2.05.27.27 (for 5.0-5.2 branch), 5.3.05.36.27 (for 5.3 branch), 5.4.05.44.27 (for 5.4 branch), or 5.5.05.52.27 (for 5.5 branch)
- Identify the current InsydeH2O kernel version by checking the firmware ROM layout or system information
- For systems running kernel 5.0-5.2.x, upgrade to version 5.2.05.27.27 or later
- For systems running kernel 5.3.x, upgrade to version 5.3.05.36.27 or later
- For systems running kernel 5.4.x, upgrade to version 5.4.05.44.27 or later
- For systems running kernel 5.5.x, upgrade to version 5.5.05.52.27 or later
- Apply the firmware update through the vendor's recommended BIOS/UEFI update process
- If immediate upgrade is not feasible, enable IOMMU in UEFI settings to mitigate DMA attacks on the ACPI runtime memory used for the command buffer
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation16.0 h
- Testing10.0 h
- Review / QA6.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2022-32470 — 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-2022-32470 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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