Microsoft Windows up to Server 2022 Hyper-V denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.2$0-$5k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Microsoft Windows up to Server 2022. This impacts an unknown function of the component Hyper-V. Such manipulation leads to denial of service. This vulnerability is uniquely identified as CVE-2021-43246. The attack can be launched remotely. No exploit exists. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability was found in Microsoft Windows up to Server 2022 (Operating System). It has been rated as critical. Affected by this issue is an unknown functionality of the component Hyper-V. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability.

The weakness was disclosed 12/14/2021 as confirmed security guidance (Website). The advisory is shared for download at portal.msrc.microsoft.com. This vulnerability is handled as CVE-2021-43246. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1499.

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). Once again VulDB remains the best source for 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: 5.9
VulDB Meta Temp Score: 5.2

VulDB Base Score: 6.3
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 5.6
Vendor Vector (Microsoft): 🔍

CVSSv2info

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

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

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 🔍
10/07/2025 +1392 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

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

CVE: CVE-2021-43246 (🔍)
GCVE (CVE): GCVE-0-2021-43246
GCVE (VulDB): GCVE-100-188252
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 06:07
Updated: 10/07/2025 15:43
Changes: 12/15/2021 06:07 (34), 12/15/2021 06:11 (21), 12/17/2021 14:58 (2), 10/07/2025 15:43 (21)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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