CVE-2021-36942
Microsoft Windows Local Security Authority (LSA) Spoofing Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 17 November 2021). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
Windows LSA Spoofing Vulnerability
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 66.02% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 3 November 2021 · due 17 November 2021 · used in ransomware campaigns
- Affected
- microsoft/windows server 2004 · microsoft/windows server 2008 · microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019 · microsoft/windows server 20h2
- Source
- secure@microsoft.com
EPSS 66.0% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2021-36942
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36942Patch, Vendor Advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36942Patch, Vendor Advisory
- https://www.kb.cert.org/vuls/id/405600Exploit, Third Party Advisory, US Government Resource
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36942US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.