CVE-2021-34500: Windows Kernel Memory Information Disclosure Vulnerability

Overview

Severity

Medium (CVSS 6.3)

CVSS Vector

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

Category

Information Disclosure

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2021-Jul

Released

2021-07-13

Last Updated

2022-02-08

EPSS Score

2.59% (percentile: 85.6%)

FAQ

What type of information could be disclosed by this vulnerability? The type of information that could be disclosed if an attacker successfully exploited this vulnerability is Guest VM to Hyper-V host server - virtualization security boundary. What type of information could be disclosed by this vulnerability? The type of information that could be disclosed if an attacker successfully exploited this vulnerability is memory from the file cache. This could include unintentional read access to memory contents in kernel space from a user mode process, and on a Hyper-V server this could result in Guest VM to Hyper-V host server memory content disclosure. According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires an attacker to win a race condition.

Affected Products (40)

Windows

• Windows 10 Version 1809 for 32-bit Systems
• Windows 10 Version 1809 for x64-based Systems
• Windows 10 Version 1809 for ARM64-based Systems
• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows 10 Version 1909 for 32-bit Systems
• Windows 10 Version 1909 for x64-based Systems
• Windows 10 Version 1909 for ARM64-based Systems
• Windows 10 Version 21H1 for x64-based Systems
• Windows 10 Version 21H1 for ARM64-based Systems
• Windows 10 Version 21H1 for 32-bit Systems
• Windows 10 Version 2004 for 32-bit Systems
• Windows 10 Version 2004 for ARM64-based Systems
• Windows 10 Version 2004 for x64-based Systems
• Windows Server, version 2004 (Server Core installation)
• Windows 10 Version 20H2 for x64-based Systems
• Windows 10 Version 20H2 for 32-bit Systems
• Windows 10 Version 20H2 for ARM64-based Systems
• Windows Server, version 20H2 (Server Core Installation)
• Windows 10 for 32-bit Systems
• Windows 10 for x64-based Systems
• Windows 10 Version 1607 for 32-bit Systems
• Windows 10 Version 1607 for x64-based Systems
• Windows Server 2016
• Windows Server 2016 (Server Core installation)
• Windows 8.1 for 32-bit systems
• Windows 8.1 for x64-based systems
• Windows RT 8.1
• Windows Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

ESU

• Windows 7 for 32-bit Systems Service Pack 1
• Windows 7 for x64-based Systems Service Pack 1
• Windows Server 2008 for 32-bit Systems Service Pack 2
• Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
• 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 (13)

• 5004244
• 5004245
• 5004237
• 5010358
• 5010359
• 5010404
• 5010422
• 5010419
• 5010395
• 5010384
• 5010403
• 5010392
• 5010412

Revision History

• 2021-07-13: Information published.
• 2022-02-08: To comprehensively address CVE-2021-34500, Microsoft has released February 2022 security updates for the following supported editions of Microsoft Windows: Windows 10, Windows 10 Version 1607, Windows 8.1, Windows Server 2012 R2, Windows Server 2012, Windows 7, Windows Server 2008 R2, and Windows Server 2008. Microsoft strongly recommends that customers install the updates to be fully protected from the vulnerability. Customers whose systems are configured to receive automatic updates do not need to take any further action.