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High 1 exploited CVE MSRC-CVE-2021-36934 1 CVE

Windows Elevation of Privilege Vulnerability

Published Jul 20, 2021 · Updated Aug 12, 2021 · Revision 7

Vendor: Microsoft

Summary

Impact: Elevation of Privilege. Microsoft rating: Important. Not known to be exploited, publicly disclosed before the fix — Exploitation More Likely. Customer action: Required.

Details

Why doesn't this security update fully mitigate this vulnerabilty?
Fully mitigating this vulnerability involves deleting shadow copies of user data. To avoid deleting data without users' consent, we have opted to allow users to delete their shadow copies themselves. See KB5005357- Delete Volume Shadow Copies.
This security update corrects the ACLs on specific system files, including the SAM database, that would allow an attacker to elevate privileges. To avoid unexpected behavior, this security update does not correct the ACLs on every file in %windir%\system32\config.
No. If you correctly applied the workaround before installing this security update, then you do not need to delete any shadow copies again.

Security updates
10.0.17763.2114 — https://support.microsoft.com/help/5005030
10.0.18363.1734 — https://support.microsoft.com/help/5005031
10.0.19043.1165 — https://support.microsoft.com/help/5005033

Vulnerabilities 1

Revision history

  1. #7

    Updated FAQ information. This is an informational change only.

  2. #6

    CVE updated to announce that Microsoft is releasing the August 2021 security updates for all affected versions of Windows to address this vulnerability. Additionally, other information has been updated to provide further instructions for mitigating this vulnerability, including the following: 1) Executive Summary has been updated 2) Workarounds have been updated 3) FAQs have been added.

  3. #5

    The following revisions have been made: 1) Removed Windows Server versions from the Security Updates table as they are not affected by this vulnerability. 2) Updated the Workaround information with a Caution regarding restoring a system from backup.

  4. #4

    In the Security Updates table, removed Windows Server, version 20H2 (Server Core Installation) because it is not affected by this vulnerability.

  5. #3

    CVE updated as follows: 1) In the Security Updates table, affected versions of Windows have been added. 2) Workaround updated to include a link to information on how to delete shadow copies. 3) FAQ removed as it is no longer applicable. This CVE will be updated when more information or updates are available.

  6. #1

    Information published.

  7. #2

    Updated Workaround information. This is an informational change only.

References