Microsoft VP9 Video Extensions information disclosure

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
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CTI Interest Score
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4.3$0-$5k0.00

Summaryinfo

A vulnerability was found in Microsoft VP9 Video Extensions. It has been classified as problematic. The affected element is an unknown function. The manipulation leads to information disclosure. This vulnerability is traded as CVE-2021-43243. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in Microsoft VP9 Video Extensions (unknown version) and classified as problematic. This issue affects an unknown code block. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality.

The weakness was shared 12/14/2021 as confirmed security guidance (Website). The advisory is shared at portal.msrc.microsoft.com. The identification of this vulnerability is CVE-2021-43243. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

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

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.3

VulDB Base Score: 4.3
VulDB Temp Score: 3.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 5.5
Vendor Vector (Microsoft): 🔍

CVSSv2info

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

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
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

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

CVE: CVE-2021-43243 (🔍)
GCVE (CVE): GCVE-0-2021-43243
GCVE (VulDB): GCVE-100-188249
CERT Bund: WID-SEC-2025-2220 - Microsoft Windows und Microsoft Windows Server: Mehrere Schwachstellen

Entryinfo

Created: 12/15/2021 06:05
Updated: 10/07/2025 18:28
Changes: 12/15/2021 06:05 (22), 12/15/2021 06:06 (12), 12/15/2021 06:09 (18), 12/17/2021 14:50 (2), 10/07/2025 18:28 (21)
Complete: 🔍
Cache ID: 216::103

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

Discussion

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