#VU55140 Improper access control in Windows and Windows Server - CVE-2021-36934

Vulnerability identifier: #VU55140

Vulnerability risk: Low

CVSSv4.0: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:A/U:Clear]

CVE-ID: CVE-2021-36934

CWE-ID: CWE-284

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
Windows
Operating systems & Components / Operating system
Windows Server
Operating systems & Components / Operating system

Vendor: Microsoft

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to overly permissive Access Control Lists (ACLs) on multiple system files, including the Security Accounts Manager (SAM) database. A local user can run arbitrary code with SYSTEM privileges.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

Windows: 10 Mobile, 10 20H2 10.0.19042.572, 10 21H1 10.0.19043.985, 10 1507 10.0.10240.16405, 10 1809 10.0.17763.1, 10 1903 10.0.18362.116, 10 1909 10.0.18363.476, 10 2004 10.0.19041.264

Windows Server: 2019 20H2 - 2019 2004

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External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36934

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.