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Known exploited vulnerability

CVE-2021-36934

highCVSS 3.1 7.8In CISA KEVEPSS 67%Published · Microsoft

The short answer

CVE-2021-36934 affects Microsoft Windows 10 Version 1809 and is rated high (CVSS 7.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2022-02-10: attackers are using it, so patch it first. The vendor has linked a patch.

What it is

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.

Severity

7.8 high

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploited (CISA KEV)

Yes, since Feb 10, 2022

Federal due date Feb 24, 2022

EPSS, next 30 days

67%

Higher than 99% of scored CVEs

How it can be exploited

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

What CISA says to do

Apply updates per vendor instructions.

Affected products

Windows 10 Version 1809, Windows 10 Version 1909, Windows 10 Version 2004, Windows 10 Version 20H2, Windows 10 Version 21H1. NVD's record lists the exact affected versions.

References

Questions

Is CVE-2021-36934 being exploited?

Yes. CISA added CVE-2021-36934 to its Known Exploited Vulnerabilities catalog on 2022-02-10, with a federal remediation due date of 2022-02-24.

How do I fix CVE-2021-36934?

CISA's required action: Apply updates per vendor instructions.

From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.

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