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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 31 Dec 2024.
Windows 10 1507Operating system · Microsoft

CVE-2024-49138

HIGH · 7.8 CVSS v3.1 Published 2024-12-12
Fix available
A fix is available. Upgrade to 10.0.10240.20857 / 10.0.14393.7606 or later.
See remediation →
96/100
Remediation priority · Urgent
In the wild Public exploit 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 an elevation of privilege vulnerability in the Windows Common Log File System (CLFS) driver. The flaw allows a local attacker to gain elevated system or kernel-level privileges, potentially executing arbitrary code with higher privileges than the current user context.

MitigationApply the Microsoft security update for CVE-2024-49138 via Windows Update or enterprise patch management. Prioritize systems with user-facing access or those exposed to lower-privilege users.

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:< 10.0.10240.20857
Windows 10 1607Operating system
Affected:< 10.0.14393.7606
Windows 10 1809Operating system
Affected:< 10.0.17763.6659
Windows 10 21h2Operating system
Affected:< 10.0.19044.5247
Windows 10 22h2Operating system
Affected:< 10.0.19045.5247
Windows 11 22h2Operating system
Affected:< 10.0.22621.4602
Windows 11 23h2Operating system
Affected:< 10.0.22631.4602
Windows 11 24h2Operating system
Affected:< 10.0.26100.2605

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. Check Windows build version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Version"' to display the installed Windows build number
    Affected if The build number is less than the fixed version for your Windows release (e.g., < 10.0.19045.5247 for Windows 10 22h2)
  2. Confirm Windows edition matches affected list
    Run 'winver' or check System Properties to identify if you are on Windows 10 1507, 1607, 1809, 21h2, 22h2, or Windows 11 22h2, 23h2, 24h2
    Affected if Your Windows edition and build combination falls within any of the vulnerable version ranges listed in the CVE
  3. Verify CLFS.sys driver is present
    Check that C:\Windows\System32\drivers\clfs.sys exists on the system
    Affected if The driver file is present (which is the default state for all affected Windows installations)

If your Windows build number is lower than the fixed build for your specific Windows version (10.0.10240.20857, 10.0.14393.7606, 10.0.17763.6659, 10.0.19044.5247, 10.0.19045.5247, 10.0.22621.4602, 10.0.22631.4602, or 10.0.26100.2605), your system is vulnerable to local privilege escalation via CLFS.sys.

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 10.0.10240.20857 / 10.0.14393.7606 / 10.0.17763.6659 or later
Fixed in 10.0.10240.2085710.0.14393.760610.0.17763.6659
Vendor patch msrc.microsoft.com →
Interim mitigation

Apply the Microsoft security update for CVE-2024-49138 via Windows Update or enterprise patch management. Prioritize systems with user-facing access or those exposed to lower-privilege users.

Recommended fix High confidence

Install the corresponding Windows security update: Windows 10 1507 -> 10.0.10240.20857+, Windows 10 1607 -> 10.0.14393.7606+, Windows 10 1809 -> 10.0.17763.6659+, Windows 10 21h2 -> 10.0.19044.5247+, Windows 10 22h2 -> 10.0.19045.5247+, Windows 11 22h2 -> 10.0.22621.4602+, Windows 11 23h2 -> 10.0.22

  1. Check current Windows version by running 'winver' or 'systeminfo' in Command Prompt
  2. Open Windows Update by pressing Win+R and typing 'ms-settings:windowsupdate'
  3. Click 'Check for updates' and install all available security updates
  4. If the specific update is not offered, manually download it from the Microsoft Update Catalog (search for CVE-2024-49138)
  5. Restart the system after installing the update
  6. Verify the fix by checking that the Windows version matches or exceeds the fixed version for your release
Caveat Standard Windows security update with no breaking changes expected; updates are cumulative monthly patches

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

Fix this in Windows 10 1507 Exploited in the wild — priority engagement
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-49138 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2024-49138 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