CVE-2021-28444: Windows Hyper-V Security Feature Bypass Vulnerability

Overview

Severity

Medium (CVSS 5.7)

CVSS Vector

CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C

Category

Security Feature Bypass

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2021-Apr

Released

2021-04-13

EPSS Score

9.65% (percentile: 92.9%)

FAQ

What configurations or versions could be at risk from this vulnerability? This bypass could affect any Hyper-V configurations that are using Router Guard. What is the exposure if the vulnerability was bypassed? Certain packets that would normally be blocked or dropped could be processed. This could allow an attacker to bypass set policy, potentially influencing router paths.

Affected Products (17)

Windows

• Windows 10 Version 1803 for x64-based Systems
• Windows 10 Version 1809 for x64-based Systems
• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows 10 Version 1909 for x64-based Systems
• Windows Server, version 1909 (Server Core installation)
• Windows 10 Version 2004 for x64-based Systems
• Windows Server, version 2004 (Server Core installation)
• Windows 10 Version 20H2 for x64-based Systems
• Windows Server, version 20H2 (Server Core Installation)
• Windows 10 for x64-based Systems
• Windows 10 Version 1607 for x64-based Systems
• Windows Server 2016
• Windows Server 2016 (Server Core installation)
• Windows 8.1 for x64-based systems
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (8)

• 5001339
• 5001342
• 5001337
• 5001330
• 5001340
• 5001347
• 5001382
• 5001393

Acknowledgments

Etienne Champetier (@champtar)

Revision History

• 2021-04-13: Information published.