VulnerabilityAnalyzed
CVE-2021-31166
Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability
KEVCRITICAL 9.8EPSS 99.8%
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 27 April 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
HTTP Protocol Stack Remote Code Execution Vulnerability
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 99.77% probability · 100th percentile
- CISA KEV
- Listed 6 April 2022 · due 27 April 2022
- Weakness
- CWE-416
- Affected
- microsoft/windows 10 2004 · microsoft/windows 10 20h2 · microsoft/windows server 2004 · microsoft/windows server 20h2
- Source
- secure@microsoft.com
CISA notes
Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2021-31166
References
- http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-Remote-Code-Execution.htmlThird Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166Patch, Vendor Advisory
- http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-Remote-Code-Execution.htmlThird Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166Patch, Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31166US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.