CVE-2021-40475

Local information disclosure

Published Oct 13, 2021 · Updated Aug 4, 2024

Information disclosure in Microsoft Windows Cloud Files Mini Filter Driver allows local users to read sensitive kernel information via a local interface. The published record does not identify the driver function or describe the incorrect operation on untrusted input. Local users require access to an affected Windows installation, and the documented impact is confidentiality loss without integrity or availability impact.

CVSS severity5.5
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Microsoft Windows Cloud Files Mini Filter Driver allows local users to read sensitive kernel information via a local interface. The published record does not identify the driver function or describe the incorrect operation on untrusted input. Local users require access to an affected Windows installation, and the documented impact is confidentiality loss without integrity or availability impact.

The record

CVE
CVE-2021-40475
Published
Oct 13, 2021
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Windows Server 2019
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.0 <10.0.17763.2237

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.0 <10.0.17763.2237
Microsoft · Windows 10 Version 21H1version=10.0.0 <10.0.19041.1288
Microsoft · Windows 10 Version 1909version=10.0.0 <10.0.18363.1854
Microsoft · Windows 11 version 21H2version=10.0.0 <10.0.22000.258
Microsoft · Windows Server, version 2004version=10.0.0 <10.0.19041.1288
Microsoft · Windows 10 Version 20H2version=10.0.0 <10.0.19041.1288
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.0 <10.0.17763.2237
Microsoft · Windows Server version 20H2version=10.0.0 <10.0.19042.1288
Microsoft · Windows Server 2022version=10.0.0 <10.0.20348.288
Microsoft · Windows 10 Version 2004version=10.0.0 <10.0.19041.1288
Microsoft · Windows 10 Version 1809version=10.0.0 <10.0.17763.2237

Published CVSS scores

5.5Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1NVDAV:L/AC:L/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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