CVEs / CVE-2021-31166
CVE-2021-31166: Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability
- Known exploited in the CISA KEV catalog since 6 Apr 2022
- high 7.5 CVSS 2.0 (NVD)
- EPSS 99.8% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Microsoft HTTP Protocol Stack contains a vulnerability in http.sys that allows for remote code execution.
Description
HTTP Protocol Stack Remote Code Execution Vulnerability
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Windows 10 Version 2004 | from 10.0.0, before 10.0.19041.982 | 10.0.19041.982 |
| Microsoft Windows Server version 2004 | from 10.0.0, before 10.0.19041.982 | 10.0.19041.982 |
| Microsoft Windows 10 Version 20H2 | from 10.0.0, before 10.0.19042.982 | 10.0.19042.982 |
| Microsoft Windows Server version 20H2 | from 10.0.0, before 10.0.19042.982 | 10.0.19042.982 |
Exploitation
| In CISA KEV since | 6 Apr 2022 |
|---|---|
| Due date for US federal agencies | 27 Apr 2022 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 2.0 | 7.5 highAV:N/AC:L/Au:N/C:P/I:P/A:PScored by NVD |
|---|---|
| Weakness | CWE-416 |
References
- CVE-2021-31166 on NVD
- CVE-2021-31166 in the CISA KEV catalog
- http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-Remote-Code-Execution.html Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166 Patch, Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31166 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.