{"id":"CVE-2021-36934","title":"An elevation of privilege vulnerability exists because of overly permissive Access Control Lists (ACLs) on multiple system files, including the Security Accounts Manager (SAM) database","summary":"An elevation of privilege vulnerability exists because of overly permissive Access Control Lists (ACLs) on multiple system files, including the Security Accounts Manager (SAM) database. An attacker who successfully exploited this vulnera…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"microsoft","product":"windows_10_1809","affected":["windows_10_1809 < 10.0.17763.2114","windows_10_1909 < 10.0.18363.1734","windows_10_2004 < 10.0.19041.1165","windows_10_20h2 < 10.0.19042.1165","windows_10_21h1 < 10.0.19043.1165"],"patched":["windows_10_1809 10.0.17763.2114","windows_10_1909 10.0.18363.1734","windows_10_2004 10.0.19041.1165","windows_10_20h2 10.0.19042.1165","windows_10_21h1 10.0.19043.1165"],"published":"2021-07-22","updated":"2026-08-10","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-36934","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36934","label":"secure@microsoft.com"},{"url":"http://packetstormsecurity.com/files/164006/HiveNightmare-AKA-SeriousSAM.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36934","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.kb.cert.org/vuls/id/506989","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36934","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","kev","in-the-wild","exploit-available"],"epss":0.67252,"epssPercentile":0.99295,"kev":true,"kevDateAdded":"2022-02-10","kevDueDate":"2022-02-24","kevRansomware":false,"exploited":true,"ingestedAt":"2026-08-11T16:47:01.027Z","exploits":{"github":24,"githubRepos":["https://github.com/HuskyHacks/ShadowSteal","https://github.com/JoranSlingerland/CVE-2021-36934","https://github.com/n3tsurge/CVE-2021-36934"],"metasploit":["post/windows/gather/credentials/windows_sam_hivenightmare"],"checkedAt":"2026-09-21T15:24:24.986Z"},"exploitAvailable":true,"slug":"CVE-2021-36934","body":"## Overview\n\nAn elevation of privilege vulnerability exists because of overly permissive Access Control Lists (ACLs) on multiple system files, including the Security Accounts Manager (SAM) database. An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.\nAn attacker must have the ability to execute code on a victim system to exploit this vulnerability.\nAfter installing this security update, you must manually delete all shadow copies of system files, including the SAM database, to fully mitigate this vulnerabilty. Simply installing this security update will not fully mitigate this vulnerability. See KB5005357- Delete Volume Shadow Copies.\n\n## Affected\n\n- `windows_10_1809 < 10.0.17763.2114`\n- `windows_10_1909 < 10.0.18363.1734`\n- `windows_10_2004 < 10.0.19041.1165`\n- `windows_10_20h2 < 10.0.19042.1165`\n- `windows_10_21h1 < 10.0.19043.1165`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `windows_10_1809 10.0.17763.2114`\n- `windows_10_1909 10.0.18363.1734`\n- `windows_10_2004 10.0.19041.1165`\n- `windows_10_20h2 10.0.19042.1165`\n- `windows_10_21h1 10.0.19043.1165`","depth":"abyssal","depthScore":81,"depthScoreParts":{"impact":42.9,"likelihood":13.5,"exploitation":25,"ransomware":0},"changes":[{"seq":4530,"id":"CVE-2021-36934","ts":1788887188041,"field":"exploit_available","old":"false","new":"true"},{"seq":3413,"id":"CVE-2021-36934","ts":1788886305692,"field":"exploit_available","old":"true","new":"false"},{"seq":2268,"id":"CVE-2021-36934","ts":1788882975181,"field":"exploit_available","old":"false","new":"true"},{"seq":1297,"id":"CVE-2021-36934","ts":1788882386994,"field":"exploit_available","old":"true","new":"false"},{"seq":411,"id":"CVE-2021-36934","ts":1788881822847,"field":"exploit_available","old":"false","new":"true"}]}