#VU53890 Improper Privilege Management in Windows and Windows Server - CVE-2021-31955

Vulnerability identifier: #VU53890

Vulnerability risk: Medium

CVSSv4.0: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:A/U:Green]

CVE-ID: CVE-2021-31955

CWE-ID: CWE-269

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 gain access to sensitive information.

The vulnerability exists due to improper privilege management. A local unprivileged user can read contents of Kernel memory from a user mode process.

Note, the vulnerability is being actively exploited in the wild.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Windows: 10 20H2 10.0.19042.572, 10 21H1 10.0.19043.985, 10 1809 10.0.17763.1, 10 1909 10.0.18363.476, 10 2004 10.0.19041.264

Windows Server: 2019 10.0.17763.1 - 2019 2004

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External links
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31955

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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.