KEV Intelligence

Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2021-36942

Windows LSA Spoofing Vulnerability

Microsoft / Windows Server 2008 R2 Service Pack 1 · affected before 6.1.7601.25685

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Severity
CVSS 7.5 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
66.0%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-36942 is an unauthenticated Windows LSA Spoofing Vulnerability affecting Microsoft Windows Server 2008 R2 Service Pack 1 and 13 other products.

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Microsoft / Windows Server 2008 R2 Service Pack 1 affected before 6.1.7601.25685.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Windows LSA Spoofing Vulnerability

Windows LSA Spoofing Vulnerability

Vendor Product Affected Status
Microsoft Windows Server 2008 R2 Service Pack 1 Before 6.1.7601.25685 Affected
Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation) Before 6.1.7601.25685 Affected
Microsoft Windows Server 2008 Service Pack 2 Before 6.0.6003.21192 Affected
Microsoft Windows Server 2008 Service Pack 2 (Server Core installation) Before 6.0.6003.21192 Affected
Microsoft Windows Server 2012 Before 6.2.9200.23435 Affected
Microsoft Windows Server 2012 (Server Core installation) Before 6.2.9200.23435 Affected
Microsoft Windows Server 2012 R2 Before 6.3.9600.20094 Affected
Microsoft Windows Server 2012 R2 (Server Core installation) Before 6.3.9600.20094 Affected
Microsoft Windows Server 2016 Before 10.0.14393.4583 Affected
Microsoft Windows Server 2016 (Server Core installation) Before 10.0.14393.4583 Affected
Microsoft Windows Server 2019 Before 10.0.17763.2114 Affected
Microsoft Windows Server 2019 (Server Core installation) Before 10.0.17763.2114 Affected
Microsoft Windows Server version 2004 Before 10.0.19041.1165 Affected
Microsoft Windows Server version 20H2 Before 10.0.19042.1165 Affected
View vendor advisory (opens in new tab)
Published
12 Aug 2021
Exploitation Reported
03 Nov 2021
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

microsoft ransomware windows cisa malware

CVE References

  • CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2021-36942
  • Windows LSA Spoofing Vulnerability msrc.microsoft.com · Vendor Advisory https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36942

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

Recorded 03 Nov 2021

Independent exploitation attestation added to the KEV Intelligence record.

Used in malware

CISA

Recorded 03 Nov 2021

Malware families have been linked to exploitation of this CVE.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
CISA First 2021-11-03 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

7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

66.0%

All CVSS Scores

CVSS v3.1 7.5 High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v2.0 5.0 Medium

AV:N/AC:L/Au:N/C:N/I:P/A:N

Timeline

From disclosure to observed exploitation

  1. KEV confirmed by CVE

    Exploitation attested by an external source

  2. Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  3. First public exploitation report

    Exploit observed in malware

  4. CVE published

    Vulnerability disclosed publicly

  5. 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.

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  • 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-2021-36942

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2021-36942",
  "confidence": "Confirmed",
  "cvss_score": 7.5,
  "cvss_estimated": false,
  "epss_score": 0.66023,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

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