What it is
CVE-2021-36934 is Windows Elevation of Privilege Vulnerability affecting Microsoft Windows 10 Version 1809 and 4 other products. An elevation of privilege vulnerability exists because of overly permissive Access...
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2021-36934
Windows Elevation of Privilege Vulnerability
Microsoft / Windows 10 Version 1809 · affected before 10.0.17763.2114
- Severity
- CVSS 7.8 · High
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 67.3%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.
Who is affected?
Microsoft / Windows 10 Version 1809 affected before 10.0.17763.2114.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Windows Elevation of Privilege Vulnerability
An elevation of privilege vulnerability exists because of overly permissive Access Control Lists (ACLs) on multiple system files, including the Security Accounts Manager (SAM) database. An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. An attacker must have the ability to execute code on a victim system to exploit this vulnerability.
After installing this security update, you must manually delete all shadow copies of system files, including the SAM database, to fully mitigate this vulnerabilty. Simply installing this security update will not fully mitigate this vulnerability. See KB5005357- Delete Volume Shadow Copies.
Vendor
Product
Affected
Status
Microsoft
Windows 10 Version 1809
Before 10.0.17763.2114
Affected
Microsoft
Windows 10 Version 1809
Before 10.0.17763.2114
Affected
Microsoft
Windows 10 Version 1909
Before 10.0.18363.1734
Affected
Microsoft
Windows 10 Version 2004
Before 10.0.19041.1165
Affected
Microsoft
Windows 10 Version 20H2
Before 10.0.19042.1165
Affected
Microsoft
Windows 10 Version 21H1
Before 10.0.19043.1165
Affected
- Published
- 22 Jul 2021
- Exploitation Reported
- 10 Feb 2022
- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
Tags
cisa
microsoft
windows
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2021-36934
- Windows Elevation of Privilege Vulnerability msrc.microsoft.com · Vendor Advisory https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36934
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CISA
Independent exploitation attestation added to the KEV Intelligence record.
Proof of concept available
GitHub
Public scanner or PoC coverage increases practical exploitability.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2022-02-10 00:00 UTC |
| CVE | 2026-08-10 15:31 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
7.8
High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
67.3%
All CVSS Scores
CVSS v3.1
7.8
High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
4.6
Medium
AV:L/AC:L/Au:N/C:P/I:P/A:P
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
Preventions/CVE-2021-36934
github · Created 2021-07-24 14:58:10 UTC · 3 stars · AI assessment 90%
C# PoC for CVE-2021-36934/HiveNightmare/SeriousSAM
Timeline
From disclosure to observed exploitation
-
KEV confirmed by CVE
Exploitation attested by an external source
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
Public PoC available
Public proof-of-concept code published
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2021-36934
Free JSON includes basic KEV fields{
"cve_id": "CVE-2021-36934",
"confidence": "Confirmed",
"cvss_score": 7.8,
"cvss_estimated": false,
"epss_score": 0.67252,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.