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Known exploited vulnerability

CVE-2021-31955

mediumCVSS 3.1 5.5In CISA KEVEPSS 81%Published · Microsoft

The short answer

CVE-2021-31955 affects Microsoft Windows 10 Version 1809 and is rated medium (CVSS 5.5). CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03: attackers are using it, so patch it first. The vendor has linked a patch.

What it is

Windows Kernel Information Disclosure Vulnerability

Weakness: CWE-497.

Severity

5.5 medium

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

Exploited (CISA KEV)

Yes, since Nov 3, 2021

Federal due date Nov 17, 2021

EPSS, next 30 days

81%

Higher than 100% 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
None
Availability impact
None

What CISA says to do

Apply updates per vendor instructions.

Affected products

Windows 10 Version 1809, Windows Server 2019, Windows Server 2019 (Server Core installation), Windows 10 Version 1909, Windows 10 Version 21H1, Windows 10 Version 2004, Windows Server version 2004, Windows 10 Version 20H2, Windows Server version 20H2. NVD's record lists the exact affected versions.

References

Questions

Is CVE-2021-31955 being exploited?

Yes. CISA added CVE-2021-31955 to its Known Exploited Vulnerabilities catalog on 2021-11-03, with a federal remediation due date of 2021-11-17.

How do I fix CVE-2021-31955?

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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