SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2021-34484

Microsoft Windows User Profile Service Privilege Escalation Vulnerability

KEVHIGH 7.8EPSS 21.8%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 21 April 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

Windows User Profile Service 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
21.83% probability · 98th percentile
CISA KEV
Listed 31 March 2022 · due 21 April 2022
Affected
microsoft/windows 10 1507 · microsoft/windows 10 1607 · microsoft/windows 10 1809 · microsoft/windows 10 1909 · microsoft/windows 10 2004 · microsoft/windows 10 20h2 · microsoft/windows 10 21h1 · microsoft/windows 7 · microsoft/windows 8.1 · microsoft/windows rt 8.1 · microsoft/windows server 2004 · microsoft/windows server 2008 · microsoft/windows server 2012 · microsoft/windows server 2016 · 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-2021-34484

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