How severe is CVE-2021-36942?

CVE-2021-36942 has a CVSS 3.1 base score of 7.5 (HIGH). EPSS estimates a 66.0% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-36942: Windows LSA Spoofing

CISA Known Exploited Vulnerabilities

Microsoft Windows Local Security Authority (LSA) Spoofing Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-11-03

Remediation due

2021-11-17

Ransomware

Known use

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-36942

Description

Microsoft Windows Local Security Authority (LSA) contains a spoofing vulnerability allowing an unauthenticated attacker to call a method on the LSARPC interface and coerce the domain controller to authenticate against another server using NTLM.

Severity

CVSS 3.1 · CNA7.5 HIGH

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

SSVC · CISA-ADP

Exploitationactive

Automatableyes

Technical impacttotal

Affected Products

Vendor	Product	Affected versions
Microsoft	Windows Server 2008 R2 Service Pack 1	6.1.7601.0 to <6.1.7601.25685
Microsoft	Windows Server 2008 R2 Service Pack 1 (Server Core installation)	6.1.7601.0 to <6.1.7601.25685
Microsoft	Windows Server 2008 Service Pack 2	6.0.6003.0 to <6.0.6003.21192
Microsoft	Windows Server 2008 Service Pack 2 (Server Core installation)	6.0.6003.0 to <6.0.6003.21192
Microsoft	Windows Server 2012	6.2.9200.0 to <6.2.9200.23435
Microsoft	Windows Server 2012 (Server Core installation)	6.2.9200.0 to <6.2.9200.23435
Microsoft	Windows Server 2012 R2	6.3.9600.0 to <6.3.9600.20094
Microsoft	Windows Server 2012 R2 (Server Core installation)	6.3.9600.0 to <6.3.9600.20094
Microsoft	Windows Server 2016	10.0.14393.0 to <10.0.14393.4583
Microsoft	Windows Server 2016 (Server Core installation)	10.0.14393.0 to <10.0.14393.4583
Microsoft	Windows Server 2019	10.0.17763.0 to <10.0.17763.2114
Microsoft	Windows Server 2019 (Server Core installation)	10.0.17763.0 to <10.0.17763.2114
Microsoft	Windows Server version 2004	10.0.0 to <10.0.19041.1165
Microsoft	Windows Server version 20H2	10.0.0 to <10.0.19042.1165

References

3 Links

Vendor advisories

Windows LSA Spoofing Vulnerability

Third-party advisories

VU#405600

Other references

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36942

Record Details

Published

2021-08-12

Last updated

2026-08-10

Assigner (CNA)

microsoft

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.