CVE-2021-31166
Confirmed PUBLISHEDHTTP Protocol Stack Remote Code Execution Vulnerability
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
HTTP Protocol Stack Remote Code Execution Vulnerability
- CVE Published
- May 11, 2021
- Exploitation Reported
- Apr 06, 2022
- CVSS
- 9.8 Critical
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| Microsoft |
Windows 10 Version 2004
|
10.0.0 to < 10.0.19041.982 |
Affected |
| Microsoft |
Windows Server version 2004
|
10.0.0 to < 10.0.19041.982 |
Affected |
| Microsoft |
Windows 10 Version 20H2
|
10.0.0 to < 10.0.19042.982 |
Affected |
| Microsoft |
Windows Server version 20H2
|
10.0.0 to < 10.0.19042.982 |
Affected |
CVE References
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31166 portal.msrc.microsoft.com · CVE Record https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CV...
- packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-Stack-R... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/162722/Microsoft-HTTP-Protocol-S...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2022-04-06 00:00 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Exploitation Status
Exploited in the wild
Recorded 2022-04-06 00:00:00 UTC · CISA
Proof of concept available
Recorded 2021-05-16 16:15:56 UTC · GitHub
Weaknesses (CWE)
-
Use After Free
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2022-03-07 18:56:52 UTC · 5 stars
CVE-2021-31166: exploitation with Powershell, Python, Ruby, NMAP and Metasploit.
github · Created 2021-10-20 07:37:46 UTC · 2 stars
Just a simple CVE-2021-31166 exploit tool
github · Created 2021-09-27 05:56:45 UTC · 19 stars
Windows HTTP协议栈远程代码执行漏洞 CVE-2021-31166
github · Created 2021-07-03 14:54:59 UTC · 7 stars
Exploit for MS Http Protocol Stack RCE vulnerability (CVE-2021-31166)
github · Created 2021-05-19 07:50:40 UTC · 5 stars
simple bash script for exploit CVE-2021-31166
github · Created 2021-05-17 23:54:12 UTC · 13 stars
HTTP Protocol Stack CVE-2021-31166
github · Created 2021-05-17 19:55:41 UTC · 3 stars
Different rules to detect if CVE-2021-31166 is being exploited
github · Created 2021-05-17 11:12:45 UTC · 9 stars
PoC for CVE-2021-31166, a remote HTTP.sys use-after-free triggered remotely. Although it was defined as remote command execution, it can only cause the system to crash.
github · Created 2021-05-16 16:15:56 UTC · 823 stars
Proof of concept for CVE-2021-31166, a remote HTTP.sys use-after-free triggered remotely.
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
00:00 UTC over 4 years ago00:00 UTC · over 4 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
16:15 UTC about 5 years ago16:15 UTC · about 5 years ago
Public PoC available
Public proof-of-concept code published
-
19:11 UTC about 5 years ago19:11 UTC · about 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 5 years ago00:00 UTC · over 5 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2021-31166
{
"cve_id": "CVE-2021-31166",
"title": "HTTP Protocol Stack Remote Code Execution Vulnerability",
"affected_vendor": "Microsoft",
"affected_product": "Windows 10 Version 2004, Windows Server version 2004, Windows 10 Version 20H2, Windows Server version 20H2",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 9.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}