CVE-2021-36934 HIGH

CVE-2021-36934: Windows Elevation of Privilege Vulnerability

Vendor Microsoft
Product Windows 10 Version 1809
KEV Status Known Exploited
Published July 22, 2021
Last update October 21, 2025

CVSS base score

7.8/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:T/RC:C

What the vulnerability does

01Description

<p>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.</p> <p>An attacker must have the ability to execute code on a victim system to exploit this vulnerability.</p> <p>After installing this security update, you <em>must</em> manually delete all shadow copies of system files, including the SAM database, to fully mitigate this vulnerabilty. <strong>Simply installing this security update will not fully mitigate this vulnerability.</strong> See <a href="https://support.microsoft.com/topic/1ceaa637-aaa3-4b58-a48b-baf72a2fa9e7">KB5005357- Delete Volume Shadow Copies</a>.</p>

CISA mandated remediation

02CISA Required Action

Apply updates per vendor instructions.

Key dates

03Disclosure timeline

July 22, 2021 CVE published
October 21, 2025 Record updated