SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2021-41357

Microsoft Win32k Privilege Escalation Vulnerability

KEVHIGH 7.8EPSS 2.08%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 16 May 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

Win32k Elevation of Privilege Vulnerability

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
2.08% probability · 80th percentile
CISA KEV
Listed 25 April 2022 · due 16 May 2022
Affected
microsoft/windows 10 2004 · microsoft/windows 10 20h2 · microsoft/windows 10 21h1 · microsoft/windows 11 21h2 · microsoft/windows server 2004 · microsoft/windows server 2022 · microsoft/windows server 20h2
Source
secure@microsoft.com

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2021-41357

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