How severe is CVE-2021-36942?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2021-36942 known to be exploited?

Yes. CVE-2021-36942 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 49 public proof-of-concept repositories are indexed.

Vulnerability in Microsoft Windows Server 2008 R2 Service Pack 1

CVE-2021-36942

Windows LSA Spoofing Vulnerability

EPSS: 0.937 (99.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:F/RL:O/RC:C.

Affected products

Microsoft Windows Server 2008 R2 Service Pack 1 — versions 6.1.0
Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core Installation) — versions 6.0.0
Microsoft Windows Server 2008 Service Pack 2 — versions 6.0.0
Microsoft Windows Server 2008 Service Pack 2 — versions 6.0.0
Microsoft Windows Server 2008 Service Pack 2 (Server Core Installation) — versions 6.0.0
Microsoft Windows Server 2012 — versions 6.2.0
Microsoft Windows Server 2012 R2 — versions 6.3.0
Microsoft Windows Server 2012 R2 (Server Core Installation) — versions 6.3.0
Microsoft Windows Server 2012 (Server Core Installation) — versions 6.2.0
Microsoft Windows Server 2016 — versions 10.0.0

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2021-11-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2021-11-17.

Required action: Apply updates per vendor instructions.

Known ransomware campaign use: yes.

Public proof-of-concept exploits

References

VU#405600 (third-party-advisory, x_refsource_CERT-VN)
portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36942 (x_refsource_MISC)

Frequently asked questions

What is CVE-2021-36942?: CVE-2021-36942 is a high-severity vulnerability in Microsoft Windows Server 2008 R2 Service Pack 1. CVSS score: 7.5/10. Published 2021-08-12.
How severe is CVE-2021-36942?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-36942 known to be exploited?: Yes. CVE-2021-36942 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 49 public proof-of-concept repositories are indexed.