CVE-2025-53147
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 · uneditedUse after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
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 confidenceUse-after-free vulnerability in Windows Ancillary Function Driver (AFD.sys) for WinSock. The flaw allows a locally authorized attacker to manipulate freed memory within the kernel driver to elevate privileges to SYSTEM level.
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< 10.0.10240.21100< 10.0.14393.8330< 10.0.17763.7678< 10.0.19044.6216< 10.0.19045.6216< 10.0.22621.5768< 10.0.22631.5768< 10.0.26100.4851CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/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 checksWork through these to decide whether this CVE applies to you.
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Check Windows version against affected rangesRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to obtain the exact Windows build number. Compare against the affected version list: Windows 10 1507 requires build >=10.0.10240.21100, 1607 requires >=10.0.14393.8330, 1809 requires >=10.0.17763.7678, 21h2 requires >=10.0.19044.6216, 22h2 requires >=10.0.19045.6216. Windows 11 22h2 requires >=10.0.22621.5768, 23h2 requires >=10.0.22631.5768, 24h2 requires >=10.0.26100.4851.Affected if The installed build number is LOWER than the minimum safe build for that Windows version branch.
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Confirm AFD.sys is presentRun 'driverquery /v | findstr "AFD"' or check C:\Windows\System32\drivers\afd.sys exists. The driver is a core component of the Windows network stack.Affected if AFD.sys exists on the system (this is true for all Windows systems with network functionality).
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Identify privileged local usersRun 'net user' to list local users, then 'net localgroup Administrators' to identify accounts with administrative privileges. The vulnerability requires an attacker with local access to execute code.Affected if The system has local user accounts beyond the built-in Administrator with access to execute code.
If the Windows build number falls below the minimum safe build for its version branch and the system has local user accounts with execution privileges, the environment is affected by this privilege escalation vulnerability.
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 · scoped10.0.10240.2110010.0.14393.833010.0.17763.7678
Apply Microsoft security updates for AFD.sys when released. Restrict local access to untrusted accounts and monitor for privilege escalation attempts.
Install the corresponding cumulative security update: Windows 10 1507 to build 10.0.10240.21100 or later | Windows 10 1607 to build 10.0.14393.8330 or later | Windows 10 1809 to build 10.0.17763.7678 or later | Windows 10 21h2 to build 10.0.19044.6216 or later | Windows 10 22h2 to build 10.0.19045.6
- Identify the current Windows version by running 'winver' or 'systeminfo' in Command Prompt
- Open Settings > Windows Update, or run 'ms-settings:windowsupdate'
- Click 'Check for updates' to download and install the latest cumulative security update
- Restart the computer when prompted to complete the installation
- Verify the update was installed by checking the installed updates list or re-running winver to confirm the version matches or exceeds the fixed version for your build
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-53147 — 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-2025-53147 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
- No weaponised exploit code, or anything meant to cause harm
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