CVE-2023-28468
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 FvbServicesRuntimeDxe in Insyde InsydeH2O with kernel 5.0 through 5.5. The FvbServicesRuntimeDxe SMM module exposes an SMI handler that allows an attacker to interact with the SPI flash at run-time from the OS.
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 confidenceThe FvbServicesRuntimeDxe SMM (System Management Mode) module in InsydeH2O UEFI firmware (kernel 5.0-5.5) exposes an SMI (System Management Interrupt) handler that can be exploited from the OS to read/write SPI flash storage at runtime, allowing an attacker with OS-level access to escalate privileges to 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>= 5.0, <= 5.5CVSS 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
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
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 UEFI firmware vendor and versionUse system information tools (like dmidecode, inxi, or UEFI setup utility) to retrieve the BIOS/UEFI firmware version and vendor. Look for 'Insyde' or 'InsydeH2O' as the vendor.Affected if The firmware vendor is InsydeH2O and the version string contains kernel 5.0 through 5.5 (e.g., version 5.0.x, 5.1.x, 5.2.x, 5.3.x, 5.4.x, or 5.5.x)
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Confirm the FvbServicesRuntimeDxe module is presentInspect the UEFI firmware image or SPI flash contents for the FvbServicesRuntimeDxe module. This may require firmware extraction tools or accessing the firmware through system management mode (SMM) introspection tools.Affected if The FvbServicesRuntimeDxe module exists in the UEFI firmware image and is included in the boot configuration
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Verify SMI handler exposureAnalyze the UEFI firmware for the SMI handler exposed by FvbServicesRuntimeDxe. Use firmware analysis tools to inspect the SMM image and check if the handler accepts input from the OS for SPI flash read/write operations.Affected if The SMI handler in FvbServicesRuntimeDxe accepts parameters from OS-level callers and can be invoked without sufficient authorization checks
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Monitor for suspicious SMM activityUse system management Mode (SMM) introspection tools or kernel modules to log SMI calls. Look for unexpected or frequent calls to handlers related to flash access (FVB services) especially from non-admin processes.Affected if There are SPI flash access SMI calls originating from OS-level processes that are not initiated by trusted system software
A system is affected if it runs InsydeH2O UEFI firmware with kernel version 5.0 through 5.5 and contains the vulnerable FvbServicesRuntimeDxe module that exposes an exploitable SMI handler for SPI flash access.
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.
From vendor dataApply vendor-supplied firmware updates from Insyde that patch the FvbServicesRuntimeDxe module to restrict unauthorized SMI handler access to SPI flash; until patched, monitor for suspicious SMM activity.
- Consultation6.0 h
- Implementation12.0 h
- Testing10.0 h
- Review / QA6.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-28468 — 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-2023-28468 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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