SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2021-33739

Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability

KEVHIGH 8.4EPSS 6.55%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 17 November 2021). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

Microsoft DWM Core Library Elevation of Privilege Vulnerability

CVSS 3.1
8.4 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
6.55% probability · 93th percentile
CISA KEV
Listed 3 November 2021 · due 17 November 2021
Affected
microsoft/windows 10 1909 · microsoft/windows 10 2004 · microsoft/windows 10 20h2 · microsoft/windows 10 21h1 · microsoft/windows server 2004 · microsoft/windows server 20h2
Source
secure@microsoft.com

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2021-33739

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.