Windows 10 1507Operating system · Microsoft

CVE-2022-24521

HIGH · 7.8 CVSS v3.1 Published 2022-04-15

Fix available

A fix is available. Upgrade to 10.0.10240.19265 / 10.0.14393.5066 or later.

See remediation →

96/100

Remediation priority · Urgent

In the wild Ransomware Zero-click Patch available

Official description

NVD · unedited

Windows Common Log File System Driver Elevation of Privilege Vulnerability

Technical summary

dbcve analysis · moderate confidence

This is a local Elevation of Privilege vulnerability in the Windows Common Log File System (CLFS) driver. The vulnerability allows a locally authenticated attacker to gain elevated SYSTEM privileges by exploiting a flaw in the kernel-mode driver.

MitigationApply the Microsoft security update for CVE-2022-24521 via Windows Update or the relevant security patch. Prioritize systems with exposed attack surfaces and verify successful deployment.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

Windows 10 1507Operating system

Affected:< 10.0.10240.19265

Windows 10 1607Operating system

Affected:< 10.0.14393.5066

Windows 10 1809Operating system

Affected:<= 10.0.17763.2803

Windows 10 1909Operating system

Affected:< 10.0.18363.2212

Windows 10 20h2Operating system

Affected:< 10.0.19042.1645

Windows 10 21h1Operating system

Affected:< 10.0.19043.1645

Windows 10 21h2Operating system

Affected:< 10.0.19044.1645

Windows 11 21h2Operating system

Affected:< 10.0.22000.613

CVSS breakdown

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?

dbcve checks

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

Check installed Windows version

Run 'winver' from command prompt or check 'systeminfo' to obtain the full OS build number

Affected if The displayed build number falls within any of the affected ranges: < 10.0.10240.19265 (1507), < 10.0.14393.5066 (1607), <= 10.0.17763.2803 (1809), < 10.0.18363.2212 (1909), < 10.0.19042.1645 (20h2), < 10.0.19043.1645 (21h1), < 10.0.19044.1645 (21h2), or < 10.0.22000.613 (Windows 11 21h2)
Verify CLFS driver presence

Confirm the Common Log File System driver (clfs.sys) exists in the system. This driver is located in the Windows System32\drivers directory and is a standard component of all affected Windows installations.

Affected if The clfs.sys driver file exists on the system (required for the vulnerability to be exploitable)
Confirm Windows Defender or security tool status

Verify Windows Defender or your endpoint protection is enabled and up to date. This vulnerability requires local code execution to chain with, so ensure real-time protection is active.

Affected if Real-time protection is disabled or the security product lacks recent definition updates, increasing exploitability

You are affected if your Windows build number is lower than the patched versions listed for your specific Windows release (10 or 11), and the CLFS driver is present on your system.

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

Remediation

dbcve · scoped

Upgrade available Upgrade to 10.0.10240.19265 / 10.0.14393.5066 / 10.0.18363.2212 or later

Fixed in 10.0.10240.1926510.0.14393.506610.0.18363.2212

Vendor patch msrc.microsoft.com →

Interim mitigation

Apply the Microsoft security update for CVE-2022-24521 via Windows Update or the relevant security patch. Prioritize systems with exposed attack surfaces and verify successful deployment.

Recommended fix High confidence

Identify the current Windows build version by running 'winver' or 'systeminfo' in Command Prompt
Download and install the appropriate Windows security update for CVE-2022-24521 from Windows Update or the Microsoft Update Catalog
For Windows 10 1507: Install update to reach build 10.0.10240.19265 or later
For Windows 10 1607: Install update to reach build 10.0.14393.5066 or later
For Windows 10 1809: Install update to reach build 10.0.17763.2803 or later
For Windows 10 1909: Install update to reach build 10.0.18363.2212 or later
For Windows 10 20h2: Install update to reach build 10.0.19042.1645 or later
For Windows 10 21h1: Install update to reach build 10.0.19043.1645 or later

Caveat Standard Windows cumulative update apply; enterprise environments should test updates in staging before broad deployment

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

Fix this in Windows 10 1507 Exploited in the wild — priority engagement

Consultation3.0 h
Implementation2.0 h
Testing4.0 h
Review / QA1.0 h

10.0 hours of engineering $1,740

Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,784.

Scan for this in your stack

Free · runs locally

dbcve dependency scanner

Check whether your project pulls in CVE-2022-24521 — 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

Primary sources

msrc.microsoft.comPatch / commit
msrc.microsoft.comPatchVendor Advisory
www.cisa.govUS Government Resource
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-24521 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2022-24521?

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

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

At a glance

Exploited in the wildOn CISA’s known-exploited list · agencies must fix by 2022-05-04

A fix existsUpgrade to 10.0.10240.19265 / 10.0.14393.5066 or later

Severity 7.8 High

Exploit likelihood EPSS, next 30 days 7.3%

Affects: Windows 10 1507

Remediation

Being exploited — close it fast

Fix this in Windows 10 1507 10 hrs · Moderate

Typical engagement from $1,740

Get it fixed fast See the full breakdown ↓

This CVE is on CISA’s actively-exploited list, so the clock is real — a vetted specialist can deliver a reviewed fix for your staging environment quickly.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

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.

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.

Check your environment

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.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References