CVE-2021-36948

Microsoft Windows Update Medic Service Privilege Escalation

7.8 HIGHActively exploited (CISA KEV)EPSS 23.3%

Published12 Aug 2021
Added to CISA KEV3 Nov 2021
Remediation due17 Nov 2021

Description

Windows Update Medic Service Elevation of Privilege Vulnerability

CVSS 3.1 breakdown

Attack vectorLocal

Attack complexityLow

Privileges requiredLow

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Microsoft Windows 10 1809< 10.0.17763.2114

Microsoft Windows 10 1909< 10.0.18363.1734

Microsoft Windows 10 2004< 10.0.19041.1165

Microsoft Windows 10 20h2< 10.0.19042.1165

Microsoft Windows 10 21h1< 10.0.19043.1165

Microsoft Windows Server 2004< 10.0.19041.1165

Microsoft Windows Server 2019< 10.0.17763.2114

Microsoft Windows Server 20h2< 10.0.19042.1165

Remediation

Fixed in

Microsoft Windows 10 1809≥ 10.0.17763.2114

Microsoft Windows 10 1909≥ 10.0.18363.1734

Microsoft Windows 10 2004≥ 10.0.19041.1165

Microsoft Windows 10 20h2≥ 10.0.19042.1165

Microsoft Windows 10 21h1≥ 10.0.19043.1165

Microsoft Windows Server 2004≥ 10.0.19041.1165

Microsoft Windows Server 2019≥ 10.0.17763.2114

Microsoft Windows Server 20h2≥ 10.0.19042.1165

Patch & vendor advisories

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36948PatchVendor Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36948PatchVendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36948US Government Resource

Frequently asked

Is CVE-2021-36948 being actively exploited?

Yes. CVE-2021-36948 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 3 Nov 2021.

How severe is CVE-2021-36948?

CVE-2021-36948 has a CVSS 3.1 base score of 7.8, rated high. EPSS estimates a 23.3% probability of exploitation.

Which products are affected by CVE-2021-36948?

Affected products include Microsoft Windows 10 1809, Microsoft Windows 10 1909, Microsoft Windows 10 2004, Microsoft Windows 10 20h2, Microsoft Windows 10 21h1, and 3 more.

How do I fix CVE-2021-36948?

Upgrade affected software to a fixed version, for example Microsoft Windows 10 1809 10.0.17763.2114, Microsoft Windows 10 1909 10.0.18363.1734, Microsoft Windows 10 2004 10.0.19041.1165 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2021-36948 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.