CVE-2022-27540
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 Time-of-Check to Time-of Use (TOCTOU) vulnerability has been identified in the HP BIOS for certain HP PC products, which might allow arbitrary code execution, denial of service, and information disclosure. HP is releasing BIOS updates to mitigate the potential vulnerability.
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 is a Time-of-Check to Time-of-Use (TOCTOU) race condition vulnerability in HP BIOS for certain HP PC products. TOCTOU vulnerabilities occur when there's a gap between the time a security check is performed and the time the check result is used, potentially allowing an attacker to manipulate the system state during that window. The vulnerability could allow arbitrary code execution, denial of service, or information disclosure.
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< 1.45< 01.26.01< 01.26.00< 1.45< 01.26.01< 1.6< 1.48< 1.6CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/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 HP laptop modelCheck the product label on the device casing, or boot into BIOS setup (press F10 during startup), or run 'wmic computersystem get model' from Windows command promptAffected if The model is one of: Elitebook 745 G4, 745 G5, 745 G6, 755 G4, 755 G5, 820 G3, 820 G4, or 828 G3
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Check the installed BIOS firmware versionFrom Windows: open BIOS setup (F10) and navigate to the Main or Information page, or run 'wmic bios get smbiosbiosversion' from command prompt. From Linux: run 'sudo dmidecode -s bios-version'Affected if You are unable to determine the BIOS version or the version shown is below the threshold for your model
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Compare your BIOS version against affected rangesCompare the version you found: Elitebook 745 G4 must be >= 1.45, 745 G5 >= 01.26.01, 745 G6 >= 01.26.00, 755 G4 >= 1.45, 755 G5 >= 01.26.01, 820 G3 >= 1.6, 820 G4 >= 1.48, 828 G3 >= 1.6Affected if Your installed firmware version is LOWER than the minimum version listed for your specific model
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Verify if BIOS is configured with standard security settingsBoot into BIOS setup (F10) and check the Security tab for configuration options related to BIOS updates or signed firmware enforcement. The TOCTOU flaw specifically relates to the update mechanismAffected if You are using a BIOS configuration that permits unsigned or unverified BIOS updates, or you have not applied HP's firmware updates
You are affected if you own an Elitebook 745 G4-G6, 755 G4-G5, 820 G3-G4, or 828 G3 and your current BIOS firmware version is below the specified threshold for your model.
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 · scoped1.601.26.0001.26.01
Apply the BIOS update provided by HP for affected PC products. HP has released BIOS updates to mitigate this vulnerability; check HP's support website for your specific model.
Update to BIOS version 1.45 (Elitebook 745 G4/755 G4), 01.26.01 (Elitebook 745 G5/755 G5), 01.26.00 (Elitebook 745 G6), 1.6 (Elitebook 820 G3/828 G3), or 1.48 (Elitebook 820 G4) or later
- 1. Identify the exact HP Elitebook model number from the affected device
- 2. Navigate to HP Support (support.hp.com) and enter the product model number
- 3. Locate the BIOS section and download the latest BIOS update matching or exceeding the fixed version for your model
- 4. Review the BIOS update release notes to confirm it addresses CVE-2022-27540
- 5. Connect the laptop to AC power to prevent interruption during the update process
- 6. Execute the BIOS update utility and follow the on-screen prompts
- 7. Allow the system to fully complete the update and restart - do not interrupt this process
- 8. Verify the installed BIOS version matches the fixed release version after restart
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2022-27540 — 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-2022-27540 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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