CVE-2022-33985
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 NvmExpressDxe software SMI handler 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 NvmExpressDxe 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. This issue was fixed in kernel 5.2: 05.27.25, kernel 5.3: 05.36.25, kernel 5.4: 05.44.25, kernel 5.5: 05.52.25 https://www.insyde.com/security-pledge/SA-2022055
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 · moderate confidenceDMA transactions targeted at input buffers for the NvmExpressDxe driver's software SMI (System Management Interrupt) handler can cause SMRAM (System Management RAM) corruption through a Time-of-Check to Time-of-Use (TOCTOU) attack. This allows an attacker with DMA capability to potentially corrupt SMRAM, which could lead to execution of arbitrary code in SMM.
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, < 5.4.05.44.25>= 5.5, < 5.5.05.52.25CVSS 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
- 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 Insyde Kernel versionUse system information tools (dmidecode, inxi, or UEFI setup) to retrieve the firmware/kernel version. For dmidecode: sudo dmidecode -s bios-version. For inxi: inxi -M. Check if the version string contains 5.2, 5.3, 5.4, or 5.5.Affected if The version falls within any of these ranges: >= 5.2 and < 5.2.05.27.25; >= 5.3 and < 5.3.05.36.25; >= 5.4 and < 5.4.05.44.25; or >= 5.5 and < 5.5.05.52.25
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Confirm NvmExpressDxe driver presenceInspect UEFI firmware image or running UEFI environment for the NvmExpressDxe driver. This may require UEFI firmware extraction tools or checking system firmware dumps. The driver handles NVMe storage controller communication.Affected if The NvmExpressDxe driver is loaded in the UEFI environment and handles NVMe devices
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Verify DMA capability exposureCheck if the system has DMA-capable devices (PCIe, Thunderbolt, FireWire, etc.) that could be leveraged by an attacker. Review system hardware listings: lspci, lsusb, or hardware documentation.Affected if DMA-capable expansion ports or devices are accessible to a potential attacker (external PCIe slots, Thunderbolt, etc.)
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Check SMRAM configurationInspect UEFI/BIOS settings for SMM isolation features. Some systems have SMRAM lock settings (via dmidecode -t bios or UEFI setup). Review whether SMRAM is properly locked.Affected if SMRAM is not locked or SMM isolation settings are disabled/weak
The system is affected if it runs Insyde Kernel firmware version within the affected ranges AND has the NvmExpressDxe driver active AND has exposed DMA capability that could reach SMRAM.
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 system firmware/UEFI to patched versions: kernel 5.2: 05.27.25, kernel 5.3: 05.36.25, kernel 5.4: 05.44.25, or kernel 5.5: 05.52.25 (or later). Contact system/OEM vendor for specific firmware updates.
Upgrade to kernel/firmware version 05.27.25 (for 5.2 branch), 05.36.25 (for 5.3 branch), 05.44.25 (for 5.4 branch), or 05.52.25 (for 5.5 branch) - depending on which branch is currently in use
- Identify the Insyde kernel/firmware version currently installed on the affected system
- Check the Insyde security advisory SA-2022055 for the corresponding fixed kernel version for your current branch
- Obtain the updated firmware/kernel image from Insyde or your system OEM that includes the fix (5.2: 05.27.25, 5.3: 05.36.25, 5.4: 05.44.25, or 5.5: 05.52.25 depending on your current branch)
- Apply the firmware update through the vendor-recommended process (typically via BIOS/UEFI flash utility or management interface)
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA8.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-33985 — 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-2022-33985 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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