Vulnerability report

Trusted Third Party Report Confirmed Confidence In CISA KEV

CVE-2021-42287

Active Directory Domain Services Elevation of Privilege Vulnerability

Microsoft / Windows Server 2008 R2 Service Pack 1 · affected before 6.1.7601.25769

Watch CVE-2021-42287 Browse KEV feed
Severity
CVSS 7.5 · High
Confidence
Confirmed
Exploit status
Trusted Third Party Report
EPSS
77.2%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-42287 is Active Directory Domain Services Elevation of Privilege Vulnerability affecting Microsoft Windows Server 2008 R2 Service Pack 1 and 14 other products.

Have exploitation attempts been observed?

Yes. Exploitation attempts have been reported for this vulnerability. Previdian lists it as a known exploited vulnerability. Listed in CISA KEV. Also reported by third-party sources. Confidence is confirmed.

Who is affected?

Affected products include Microsoft / Windows Server 2008 R2 Service Pack 1 and 14 other products, including affected before 6.1.7601.25769, affected before 6.0.6003.21282, and affected before 6.2.9200.23517.

What should we do?

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

Overview

Active Directory Domain Services Elevation of Privilege Vulnerability

Active Directory Domain Services Elevation of Privilege Vulnerability

Microsoft Affected
Windows Server 2008 R2 Service Pack 1
Before 6.1.7601.25769
Microsoft Affected
Windows Server 2008 R2 Service Pack 1 (Server Core installation)
Before 6.1.7601.25769
Microsoft Affected
Windows Server 2008 Service Pack 2
Before 6.0.6003.21282
Microsoft Affected
Windows Server 2008 Service Pack 2 (Server Core installation)
Before 6.0.6003.21282
Microsoft Affected
Windows Server 2012
Before 6.2.9200.23517
Microsoft Affected
Windows Server 2012 (Server Core installation)
Before 6.2.9200.23517
Microsoft Affected
Windows Server 2012 R2
Before 6.3.9600.20174
Microsoft Affected
Windows Server 2012 R2 (Server Core installation)
Before 6.3.9600.20174
Microsoft Affected
Windows Server 2016
Before 10.0.14393.4770
Microsoft Affected
Windows Server 2016 (Server Core installation)
Before 10.0.14393.4770
Microsoft Affected
Windows Server 2019
Before 10.0.17763.2300
Microsoft Affected
Windows Server 2019 (Server Core installation)
Before 10.0.17763.2300
Microsoft Affected
Windows Server 2022
Before 10.0.20348.350
Microsoft Affected
Windows Server version 2004
Before 10.0.19041.1348
Microsoft Affected
Windows Server version 20H2
Before 10.0.19041.1348
View vendor advisory (opens in new tab)
Published
10 Nov 2021
Exploitation Attempts Reported
11 Apr 2022
Attack vector
Remote
Complexity
High
Privileges
Low
User interaction
None

Tags

microsoft cisa windows ransomware malware

CVE References

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation Attempts Observed in the Wild

CISA

Recorded 11 Apr 2022

A trusted third party reported exploitation attempts.

Targeted by Malware-Related Exploitation Attempts

CISA

Recorded 11 Apr 2022

Exploitation attempts against this vulnerability are associated with malware-related payloads.

Known exploited vulnerability sources

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

Learn about Pro API access
Source Added
CISA First 2022-04-11 00:00 UTC
CVE 2026-08-06 04:30 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian 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

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

77.2%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

All CVSS Scores

CVSS v3.1 7.5 High

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

CVSS v2.0 6.5 Medium

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

Timeline

From disclosure to observed exploitation attempts

  1. 04:30 UTC

    KEV confirmed by CVE

    Exploitation attempts reported by an external source

  2. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  3. 00:00 UTC

    Targeted by malware-related exploitation attempts

    Malware-related exploitation attempts or payloads reported

  4. 00:47 UTC

    CVE published

    Vulnerability disclosed publicly

  5. 00:00 UTC

    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.

Start 14-day Pro trial Read API docs
  • 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-2021-42287

Sample API response 
{
  "cve_id": "CVE-2021-42287",
  "confidence": "Confirmed",
  "cvss_score": 7.5,
  "cvss_estimated": false,
  "epss_score": 0.7717,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}