{
  "id": "CVE-2021-36934",
  "url": "https://spydr.io/cve/CVE-2021-36934",
  "published": "2021-07-22T07:15:11.013Z",
  "modified": "2026-08-10T20:19:00.610Z",
  "score": 7.8,
  "severity": "high",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "score_source": "microsoft.com",
  "epss": 0.67252,
  "epss_percentile": 0.99289,
  "exploited": true,
  "kev": {
    "added": "2022-02-10",
    "due": "2022-02-24",
    "action": "Apply updates per vendor instructions.",
    "ransomware": "Unknown",
    "name": "Microsoft Windows SAM Local Privilege Escalation Vulnerability",
    "notes": "https://nvd.nist.gov/vuln/detail/CVE-2021-36934"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "Microsoft"
  ],
  "products": [
    "Microsoft Windows 10 Version 1809",
    "Microsoft Windows 10 Version 1909",
    "Microsoft Windows 10 Version 2004",
    "Microsoft Windows 10 Version 20H2",
    "Microsoft Windows 10 Version 21H1"
  ],
  "cwes": [],
  "description": "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 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. An attacker must have the ability to execute code on a victim system to exploit this vulnerability. After 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.",
  "status": "Analyzed",
  "score_type": "Secondary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 7.8,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36934",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/164006/HiveNightmare-AKA-SeriousSAM.html",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36934",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.kb.cert.org/vuls/id/506989",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36934",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-36934",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}