CVE-2023-25494
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 · uneditedA potential vulnerability were reported in the BIOS of some Desktop, Smart Edge, and ThinkStation products that could allow a local attacker with elevated privileges to write to NVRAM variables.
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 confidenceThis BIOS vulnerability in Lenovo Desktop, Smart Edge, and ThinkStation products allows a local attacker with elevated privileges to write to NVRAM variables. NVRAM stores critical firmware configuration settings including boot parameters, so arbitrary writes could enable persistent firmware-level persistence, boot order manipulation, or security bypass.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- Local
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/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 your Lenovo system modelRun 'systeminfo' (Windows) or check /proc/cpuinfo (Linux) or physically check the system label to confirm it is a Lenovo Desktop, Smart Edge, or ThinkStation productAffected if The system is not a Lenovo Desktop, Smart Edge, or ThinkStation - this CVE does not apply
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Check the installed BIOS/firmware versionOn Windows, run 'wmic bios get smbiosbiosversion' or check in BIOS/UEFI setup. On Linux, run 'dmidecode -s bios-version' or check /sys/class/dmi/id/bios_versionAffected if You cannot determine the BIOS version or the version is unknown - further investigation required against Lenovo's advisory for your specific model
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Determine if NVRAM variables are accessible or writableOn systems with UEFI, attempt to read NVRAM variables via 'efivar -l' (Linux) or check via 'bcdedit /enum firmware' (Windows). Note that this check requires elevated privileges and should only be performed by authorized security personnel in an authorized environmentAffected if NVRAM variables can be written by elevated but non-admin users, indicating the vulnerability may be present
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Audit current NVRAM boot configurationReview boot entries in UEFI/BIOS NVRAM via 'bcdedit /enum all' (Windows) or 'efibootmgr -v' (Linux) to check for unauthorized or unexpected boot entriesAffected if Unexpected boot entries exist, entries point to unauthorized media, or boot order has been modified without authorized change control
You are affected if you run a Lenovo Desktop, Smart Edge, or ThinkStation system where elevated privileges can write to NVRAM variables, and your BIOS/firmware version falls within the affected range listed in Lenovo's security advisory for CVE-2023-25494.
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 the vendor-supplied BIOS/firmware update from Lenovo to patch the vulnerability. Since the attack requires elevated privileges, prioritize updating systems in high-risk environments and enforce least-privilege access controls.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2023-25494 — 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-2023-25494 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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