CVE-2021-36934 — Windows Elevation of Privilege Vulnerability

Executive 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 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.

Overview

7.8

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

More Likely

MS Exploit Likelihood

Category Elevation of Privilege

Released Jul 13 2021

Last Updated Jul 13 2021

Publicly Disclosed Yes

CISA KEV Not Listed

Known Exploits None Known

NVD CVSS 7.8 HIGH — matches MSRC

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

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Functional

REMEDIATION LEVEL

Temporary Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 7.3

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

14 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1809 for 32-bit Systems	`5005030 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for x64-based Systems	`5005030 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for ARM64-based Systems	`5005030 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for 32-bit Systems	`5005031 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for x64-based Systems	`5005031 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1909 for ARM64-based Systems	`5005031 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H1 for x64-based Systems	`5005033 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H1 for ARM64-based Systems	`5005033 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H1 for 32-bit Systems	`5005033 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 2004 for 32-bit Systems	`5005033 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 2004 for ARM64-based Systems	`5005033 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 2004 for x64-based Systems	`5005033 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 20H2 for 32-bit Systems	`5005033 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 20H2 for ARM64-based Systems	`5005033 (Security Update)`	Important	Elevation of Privilege	Yes

Patches

3 patches

Article	Type	Restart
`5005030`	Security Update	Yes
`5005031`	Security Update	Yes
`5005033`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Microsoft has not published researcher acknowledgments for this CVE, or they are not yet reflected in our data source. Check the MSRC advisory directly for the most current credit information.

References

MSRC Advisory MITRE NVD