SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2021-1732

Microsoft Win32k Privilege Escalation Vulnerability

KEVHIGH 7.8EPSS 78.4%

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

Windows 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
78.38% probability · 100th percentile
CISA KEV
Listed 3 November 2021 · due 17 November 2021 · used in ransomware campaigns
Weakness
CWE-787
Affected
microsoft/windows 10 1803 · microsoft/windows 10 1809 · microsoft/windows 10 1909 · microsoft/windows 10 2004 · microsoft/windows 10 20h2 · microsoft/windows server 1909 · microsoft/windows server 2004 · microsoft/windows server 2019 · microsoft/windows server 20h2
Source
secure@microsoft.com

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2021-1732

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