Microsoft Windows up to Server 2019 Hyper-V access control

Summaryinfo

A vulnerability has been found in Microsoft Windows and classified as critical. This vulnerability affects unknown code of the component Hyper-V. Performing a manipulation results in access control. This vulnerability is reported as CVE-2020-16891. The attack requires a local approach. No exploit exists. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability was found in Microsoft Windows (Operating System). It has been classified as critical. This affects an unknown part of the component Hyper-V. The manipulation with an unknown input leads to a access control vulnerability. CWE is classifying the issue as CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

<p>A remote code execution vulnerability exists when Windows Hyper-V on a host server fails to properly validate input from an authenticated user on a guest operating system. To exploit the vulnerability, an attacker could run a specially crafted application on a guest operating system that could cause the Hyper-V host operating system to execute arbitrary code.</p> <p>An attacker who successfully exploited the vulnerability could execute arbitrary code on the host operating system.</p> <p>The security update addresses the vulnerability by correcting how Hyper-V validates guest operating system user input.</p>

The weakness was disclosed 10/13/2020 as confirmed security guidance (Website). It is possible to read the advisory at portal.msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2020-16891. The exploitability is told to be easy. Attacking locally is a requirement. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/24/2026). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK. The advisory points out:

A remote code execution vulnerability exists when Windows Hyper-V on a host server fails to properly validate input from an authenticated user on a guest operating system. To exploit the vulnerability, an attacker could run a specially crafted application on a guest operating system that could cause the Hyper-V host operating system to execute arbitrary code. An attacker who successfully exploited the vulnerability could execute arbitrary code on the host operating system. The security update addresses the vulnerability by correcting how Hyper-V validates guest operating system user input.

It is declared as proof-of-concept.

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

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 7 SP1
• 10
• 10 1607
• 10 1709
• 10 1803
• 10 1809
• 10 1903
• 10 1909
• 10 2004
• Server 1903
• Server 1909
• Server 2004
• Server 2008 R2 SP1
• Server 2008 SP2
• Server 2016
• Server 2019

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

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