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Findings

CVE-2021-36934

Microsoft Windows SAM Local Privilege Escalation Vulnerability

Published Jul 22, 2021 · updated Aug 10, 2026 · microsoft windows 10 1809

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.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 22, 2021 · Catalog

    Detected

    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 use

  2. Feb 10, 2022 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. Feb 24, 2022 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Aug 10, 2026 · Catalog

    Updated

    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 use

Required action

Apply updates per vendor instructions.

CISA due date Feb 24, 2022

Affected

  • cpe microsoft/windows 10 1809version unspecified
  • cpe microsoft/windows 10 1909version unspecified
  • cpe microsoft/windows 10 2004version unspecified
  • cpe microsoft/windows 10 20h2version unspecified
  • cpe microsoft/windows 10 21h1version unspecified
  • vendor Microsoft Windowsversion unspecified

Sources

  • CISA KEVCVE-2021-36934

    If a Volume Shadow Copy (VSS) shadow copy of the system drive is available, users can read the SAM file which would allow any user to escalate privileges to SYSTEM level.

    cisa.gov
  • CVE.orgCVE-2021-36934

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2021-36934

    30-day exploitation probability 67.3%

    first.org
  • Metasploit Modulespost_windows/gather/credentials/windows_sam_hivenightmare

    Public module reference (normal). Module source is not copied into this catalog.

    rapid7.com
  • NIST NVDCVE-2021-36934

    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

    nvd.nist.gov
  • Packet Storm Securityhttp://packetstormsecurity.com/files/164006/HiveNightmare-AKA-SeriousSAM.html

    Packet Storm link already published on the finding.

    packetstormsecurity.com

References