CVE-2021-31971: Windows HTML Platforms Security Feature Bypass Vulnerability

Overview

Severity

Medium (CVSS 6.8)

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/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-Jun

Released

2021-06-08

EPSS Score

5.71% (percentile: 90.4%)

FAQ

The Security Updates table indicates that this vulnerability affects all supported versions of Microsoft Windows. Why are IE Cumulative updates listed for Windows Server 2008, Windows 7, Windows Server 2008 R2, Windows Server 2012, Windows 8.1, and Windows Server 2012 R2? While Microsoft has announced retirement of the Internet Explorer 11 application on certain platforms and the Microsoft Edge Legacy application is deprecated, the underlying MSHTML, EdgeHTML, and scripting platforms are still supported. The MSHTML platform is used by Internet Explorer mode in Microsoft Edge as well as other applications through WebBrowser control. The EdgeHTML platform is used by WebView and some UWP applications. The scripting platforms are used by MSHTML and EdgeHTML but can also be used by other legacy applications. Updates to address vulnerabilities in the MSHTML platform and scripting engine are included in the IE Cumulative Updates; EdgeHTML and Chakra changes are not applicable to those platforms. To stay fully protected, we recommend that customers who install Security Only updates install the IE Cumulative updates for this vulnerability.

Affected Products (30)

ESU

• Windows Server 2012 R2
• Windows Server 2012
• Windows 7 for 32-bit Systems Service Pack 1
• Windows Server 2008 for 32-bit Systems Service Pack 2
• Windows 7 for x64-based Systems Service Pack 1
• Windows Server 2008 R2 for x64-based Systems Service Pack 1
• Windows Server 2008 for x64-based Systems Service Pack 2

Windows

• Windows 10 Version 1607 for 32-bit Systems
• Windows 8.1 for 32-bit systems
• Windows Server 2016
• Windows 10 Version 1607 for x64-based Systems
• Windows RT 8.1
• Windows 10 for 32-bit Systems
• Windows 10 for x64-based Systems
• Windows 8.1 for x64-based systems
• Windows 10 Version 21H1 for 32-bit Systems
• Windows 10 Version 21H1 for x64-based Systems
• Windows 10 Version 21H1 for ARM64-based Systems
• Windows 10 Version 2004 for x64-based Systems
• Windows 10 Version 2004 for 32-bit Systems
• Windows 10 Version 20H2 for ARM64-based Systems
• Windows 10 Version 1809 for 32-bit Systems
• Windows Server 2019
• Windows 10 Version 1809 for x64-based Systems
• Windows 10 Version 2004 for ARM64-based Systems
• Windows 10 Version 1909 for x64-based Systems
• Windows 10 Version 1909 for ARM64-based Systems
• Windows 10 Version 1909 for 32-bit Systems
• Windows 10 Version 20H2 for 32-bit Systems
• Windows 10 Version 1809 for ARM64-based Systems

Security Updates (10)

• 5003671
• 5003636
• 5003697
• 5003638
• 5003667
• 5003661
• 5003687
• 5003637
• 5003646
• 5003635

Acknowledgments

Marcus Brinkmann (Ruhr University Bochum), Christian Dresen (Münster University of Applied Sciences), Robert Merget (Ruhr University Bochum), Damian Poddebniak (Münster University of Applied Sciences), Jens Müller (Ruhr University Bochum), Juraj Somorovsky (Paderborn University), Jörg Schwenk (Ruhr University Bochum), Sebastian Schinzel (Münster University of Applied Sciences)

Revision History

• 2021-06-08: Information published.