Microsoft Windows up to Server 2022 Common Log File System Driver privilege escalation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.7$5k-$25k0.00

Summaryinfo

A vulnerability has been found in Microsoft Windows and classified as very critical. Affected by this issue is some unknown functionality of the component Common Log File System Driver. This manipulation causes an unknown weakness. This vulnerability appears as CVE-2021-43226. The attack may be initiated remotely. In addition, an exploit is available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in Microsoft Windows (Operating System). It has been declared as very critical. Affected by this vulnerability is an unknown part of the component Common Log File System Driver. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Windows Common Log File System Driver Elevation of Privilege Vulnerability

The weakness was presented 12/14/2021 as confirmed security guidance (Website). The advisory is shared at portal.msrc.microsoft.com. This vulnerability is known as CVE-2021-43226. Technical details are unknown but an exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/30/2025).

It is declared as attacked. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 10/06/2025 with a due date of 10/27/2025:

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-2220). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Microsoft Windows 7 x64 Edition Service Pack 1
  • Microsoft Windows RT 8.1
  • Microsoft Windows 8.1 for x64-based Systems
  • Microsoft Windows 10
  • Microsoft Windows Server 2012
  • Microsoft Windows Server 2016
  • Hitachi Storage
  • Microsoft Windows Server 2008 Service Pack 2
  • Microsoft Windows Server 2008 R2
  • Microsoft Windows Server 2019
  • Microsoft Windows Server 2012 R2
  • Microsoft Windows Server
  • Microsoft Windows Server 2022
  • Microsoft Windows 11

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.1
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.8
Vendor Vector (Microsoft): 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CNA Base Score: 7.8
CNA Vector (Microsoft): 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

11/02/2021 🔍
12/14/2021 +42 days 🔍
12/14/2021 +0 days 🔍
12/15/2021 +0 days 🔍
10/30/2025 +1415 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: portal.msrc.microsoft.com
Status: Confirmed

CVE: CVE-2021-43226 (🔍)
GCVE (CVE): GCVE-0-2021-43226
GCVE (VulDB): GCVE-100-188233
CERT Bund: WID-SEC-2025-2220 - Microsoft Windows und Microsoft Windows Server: Mehrere Schwachstellen

scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 12/15/2021 05:49
Updated: 10/30/2025 21:41
Changes: 12/15/2021 05:49 (27), 12/15/2021 05:50 (6), 12/15/2021 05:53 (21), 12/17/2021 14:02 (2), 10/06/2025 20:34 (30), 10/07/2025 04:02 (28), 10/07/2025 15:50 (7), 10/30/2025 21:41 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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