CVE-2021-28476: Windows Hyper-V Remote Code Execution Vulnerability

Overview

Severity

Critical (CVSS 9.9)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C

Category

Remote Code Execution

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2021-May

Released

2021-05-11

EPSS Score

63.91% (percentile: 98.4%)

FAQ

Under what circumstances might this vulnerability be exploited other than as a denial of service attack against a Hyper-V host? This issue allows a guest VM to force the Hyper-V host's kernel to read from an arbitrary, potentially invalid address. The contents of the address read would not be returned to the guest VM. In most circumstances, this would result in a denial of service of the Hyper-V host (bugcheck) due to reading an unmapped address. It is possible to read from a memory mapped device register corresponding to a hardware device attached to the Hyper-V host which may trigger additional, hardware device specific side effects that could compromise the Hyper-V host's security.

Detection & Weaponization (1 sources)

Maturity: Exploit

• GitHub PoC: 4 repositories

Affected Products (23)

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 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
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

ESU

• Windows 7 for x64-based Systems Service Pack 1
• Windows Server 2008 for x64-based Systems Service Pack 2
• Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
• Windows Server 2008 R2 for x64-based Systems Service Pack 1
• Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)

Security Updates (14)

• 5003174
• 5003171
• 5003169
• 5003173
• 5003172
• 5003197
• 5003233
• 5003228
• 5003209
• 5003220
• 5003210
• 5003225
• 5003208
• 5003203

Acknowledgments

Peleg Hadar (<a href="https://twitter.com/peleghd">@peleghd</a>) of SafeBreach Labs and Ophir Harpaz (<a href="https://twitter.com/OphirHarpaz">@OphirHarpaz</a>) of Guardicore Labs, <a href="https://twitter.com/ergot86">Daniel Fernandez Kuehr</a> of Blue Frost Security GmbH, Leo Adrien (<a href="https://twitter.com/australeo">@australeo</a>)

Revision History

• 2021-05-11: Information published.