CVE-2021-31166

HTTP Protocol Stack Remote Code Execution Vulnerability

CVE-2021-31166 is fixed in 7 products on 1 platform, first by KB5003173, released May 11, 2021. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on April 6, 2022. Patch Radar priority: Patch now.

Patch nowCISA KEV

CVSS

9.8

Critical

Exploitation

Exploited

Listed by CISA

CISA KEV

Apr 6, 2022

Federal due date Apr 27, 2022

EPSS

0.9987

99th percentile

Where it's fixed

Product	Fix	Released
Microsoft
Windows 10 Version 2004 for 32-bit Systems	KB5003173	May 11, 2021
Windows 10 Version 2004 for ARM64-based Systems	KB5003173	May 11, 2021
Windows 10 Version 2004 for x64-based Systems	KB5003173	May 11, 2021
Windows 10 Version 20H2 for 32-bit Systems	KB5003173	May 11, 2021
Windows 10 Version 20H2 for ARM64-based Systems	KB5003173	May 11, 2021
Windows Server, version 2004 (Server Core installation)	KB5003173	May 11, 2021
Windows Server, version 20H2 (Server Core Installation)	KB5003173	May 11, 2021

Details

Published
May 11, 2021
CISA required action
Apply updates per vendor instructions.
Vendor advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-31166

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