Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 7 Mar 2023. Known ransomware use
Windows 10 1507Operating system · Microsoft

CVE-2023-23376

HIGH · 7.8 CVSS v3.1 Published 2023-02-14
Fix available
A fix is available. Upgrade to 10.0.10240.19747 / 10.0.14393.5717 or later.
See remediation →
96/100
Remediation priority · Urgent
In the wild Ransomware Zero-click Patch available

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 · unedited
Windows Common Log File System Driver Elevation of Privilege 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 confidence

This is a local Elevation of Privilege vulnerability in the Windows Common Log File System (CLFS) driver (clfs.sys). The vulnerability allows an authenticated local attacker to execute arbitrary code with elevated (SYSTEM) privileges by exploiting a flaw in the CLFS driver.

MitigationApply the Microsoft security update KB5002537 or subsequent relevant Windows security patches addressing CVE-2023-23376 to all affected Windows systems.

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
Windows 10 1507Operating system
Affected:< 10.0.10240.19747
Windows 10 1607Operating system
Affected:< 10.0.14393.5717
Windows 10 1809Operating system
Affected:< 10.0.17763.4010
Windows 10 20h2Operating system
Affected:< 10.0.19042.2604
Windows 10 21h2Operating system
Affected:< 10.0.19044.2604
Windows 10 22h2Operating system
Affected:< 10.0.19045.2604
Windows 11 21h2Operating system
Affected:< 10.0.22000.1574
Windows 11 22h2Operating system
Affected:< 10.0.22621.1265

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed Windows version
    Run 'winver' from the command prompt or 'systeminfo' and locate the 'OS Version' field. Alternatively, run 'reg query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" /v CurrentBuild' to get the build number.
    Affected if The build number is less than the thresholds in the affected versions list (e.g., below 19045 for Windows 10 22h2, below 22621 for Windows 11 22h2).
  2. Check the CLFS driver file version
    Right-click clfs.sys in C:\Windows\System32, select Properties, then Details. Alternatively, run 'powershell (Get-Item C:\Windows\System32\clfs.sys).VersionInfo | Select-Object FileVersion'.
    Affected if The file version is lower than the patched version corresponding to your Windows build (the patched versions match the threshold build numbers in the affected products list).
  3. Verify security update installation
    Run 'powershell Get-HotFix | Where-Object {$_.Description -eq "Security Update"} | Sort-Object InstalledOn -Descending | Select-Object -First 10' to list recent security updates. Look for updates from March 2023 or later that correspond to CVE-2023-23376.
    Affected if No security update related to CVE-2023-23376 from March 2023 or later is installed.

The system is vulnerable if it runs an affected Windows version (10 1507 through 22h2, or Windows 11 21h2/22h2) with a build number below the threshold and lacks the March 2023 security update for CVE-2023-23376.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 10.0.10240.19747 / 10.0.14393.5717 / 10.0.17763.4010 or later
Fixed in 10.0.10240.1974710.0.14393.571710.0.17763.4010
Vendor patch msrc.microsoft.com →
Interim mitigation

Apply the Microsoft security update KB5002537 or subsequent relevant Windows security patches addressing CVE-2023-23376 to all affected Windows systems.

Recommended fix High confidence

Apply March 2023 Windows Security Update (KB5003706) or later; specific build numbers: Windows 10 1507 (10.0.10240.19747), Windows 10 1607 (10.0.14393.5717), Windows 10 1809 (10.0.17763.4010), Windows 10 20h2 (10.0.19042.2604), Windows 10 21h2 (10.0.19044.2604), Windows 10 22h2 (10.0.19045.2604), Wi

  1. 1. Identify the current Windows version by running 'winver' or 'systeminfo' in Command Prompt
  2. 2. Navigate to Settings > Update & Security > Windows Update
  3. 3. Click 'Check for updates' to receive the latest security patches
  4. 4. Install all available updates, ensuring the March 2023 or later Security Update is included
  5. 5. Restart the system when prompted to complete the installation
  6. 6. Verify the installed KB number matches Microsoft's security bulletin for CVE-2023-23376 (KB5003706 or subsequent updates)

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1507 Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-23376 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-23376 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data