⚠ Actively exploited
Added to CISA KEV on 2022-04-06. Federal agencies required to patch by 2022-04-27. Required action: Apply updates per vendor instructions..

CVE-2021-31166

CWE-416 — Use After Free13 documents11 sources
Severity
9.8CRITICAL
EPSS
93.0%
top 0.22%
CISA KEV
KEV
Added 2022-04-06
Due 2022-04-27
Exploit
Exploited in wild
Active exploitation observed
Affected products
8
Microsoft Windows 10 Version 2004Microsoft Windows 10 Version 20h2Microsoft Windows Server Version 2004+5 more
Timeline
PublishedMay 11
KEV addedApr 6
KEV dueApr 27
Latest updateMay 24
CISA Required Action: Apply updates per vendor instructions.

Description

HTTP Protocol Stack Remote Code Execution Vulnerability

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages7 packages

▶NVDmicrosoft/windows< 10.0.19041.982+1
▶NVDmicrosoft/windows_10_2004< 10.0.19041.982
▶NVDmicrosoft/windows_10_20h2< 10.0.19042.982
▶CVEListV5microsoft/windows_10_version_200410.0.0 — 10.0.19041.982
▶CVEListV5microsoft/windows_10_version_20h210.0.0 — 10.0.19042.982

Patches

Patch: portal.msrc.microsoft.com ↗Patch: portal.msrc.microsoft.com ↗

🔴Vulnerability Details

3
GHSA
GHSA-3mj9-c62w-jw5w: HTTP Protocol Stack Remote Code Execution Vulnerability↗2022-05-24
▶
CVEList
HTTP Protocol Stack Remote Code Execution Vulnerability↗2021-05-11
▶
VulnCheck
Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability↗2021
▶

💥Exploits & PoCs

1
Metasploit
Windows IIS HTTP Protocol Stack DOS↗
▶

🔍Detection Rules

1
Suricata
ET EXPLOIT Windows HTTP Protocol Stack UAF/RCE (CVE-2021-31166), http.sys DOS (CVE-2022-21907) Inbound↗2021-05-17
▶

📋Vendor Advisories

2
CISA
Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability↗2022-04-06
▶
Microsoft
HTTP Protocol Stack Remote Code Execution Vulnerability↗2021-05-11
▶