{"id":"CVE-2021-36942","published":"2021-08-12T18:15:10Z","modified":"2026-08-10T20:19:03Z","title":"Microsoft Windows Local Security Authority (LSA) Spoofing Vulnerability","vendor":"Microsoft","product":"Windows","tier":"core","eol":null,"description":{"text":"Windows LSA Spoofing Vulnerability","provenance":"source","from":"NVD"},"summary":{"text":"The Microsoft Windows Local Security Authority (LSA) component contains a spoofing vulnerability. An attacker who can reach the affected system over the network can exploit it without authentication or user interaction, with the vector indicating a high impact to confidentiality.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T06:59:48Z"},"cvss":{"score":7.5,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","provenance":"source","from":"NVD"},"epss":{"score":0.66023,"percentile":0.99271,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","ransomware":true,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-36942","provenance":"source"},"vulncheckKev":{"dateAdded":"2021-08-24","exploitedFirstSeen":"2021-08-24","ransomware":true,"evidence":[{"url":"https://cisa.gov/news-events/alerts/2021/08/10/microsoft-releases-august-2021-security-updates","date":"2021-08-24"},{"url":"https://www.cybereason.com/blog/threat-alert-microsoft-exchange-proxyshell-exploits-and-lockfile-ransomware","date":"2021-08-30"},{"url":"https://www.securin.io/microsoft-exchange-proxyshell-and-windows-petitpotam-vulnerabilities-chained-in-new-attack/","date":"2021-09-15"},{"url":"https://blog.talosintelligence.com/2021/11/babuk-exploits-exchange.html","date":"2021-11-03"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2021-11-03"},{"url":"https://cybersecurityworks.com/howdymanage/uploads/file/csw_final_ransomware_index-update-q321-csw_.pdf","date":"2021-11-10"},{"url":"https://cybersecurityworks.com/howdymanage/uploads/file/ransomware-_-2022-spotlight-report_compressed.pdf","date":"2022-01-26"},{"url":"https://www.paloaltonetworks.com/content/dam/pan/en_US/assets/pdf/reports/2022-unit42-ransomware-threat-report-final.pdf","date":"2022-03-24"},{"url":"https://static.tenable.com/marketing/whitepapers/Whitepaper-Ransomware_Ecosystem.pdf","date":"2022-06-22"},{"url":"https://info.securin.io/hubfs/Securin%20Ransomware%20Report%202023.pdf","date":"2023-02-14"}],"evidenceTotal":15,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-749","name":"Exposed Dangerous Method or Function"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36942","tags":["Patch","Vendor Advisory"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36942","tags":["Patch","Vendor Advisory"]},{"url":"https://www.kb.cert.org/vuls/id/405600","tags":["Exploit","Third Party Advisory","US Government Resource"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36942","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Network-reachable spoofing flaw, no auth required","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"Windows LSA Spoofing Vulnerability","start":0,"end":34}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1557","name":"Adversary-in-the-Middle","tactics":["collection","credential-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Spoofing enables adversary-in-the-middle interception","mappingType":"primary_impact","evidence":[{"from":"description","quote":"Windows LSA Spoofing Vulnerability","start":0,"end":34}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-23518","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-23518","exploited":true,"exploitedSince":"2021-11-03","provenance":"source"},"exploits":[],"exploitSources":{"metasploit":[{"name":"PetitPotam","module":"auxiliary/scanner/dcerpc/petitpotam","type":"auxiliary","disclosureDate":null,"url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/scanner/dcerpc/petitpotam.rb"}],"provenance":"source"},"exploitRefs":["https://www.kb.cert.org/vuls/id/405600"],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1557"],"provenance":"ai"}],"timeline":[{"date":"2021-08-12","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-36942","provenance":"source"},{"date":"2021-08-24","kind":"exploited-reported","label":"Exploitation first reported 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reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD reference tagged Exploit; 1 Metasploit module"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":5.25,"detail":"base score 7.5"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}