CVE-2021-36948
published 2021-08-12CVE-2021-36948: Windows Update Medic Service Elevation of Privilege Vulnerability
PriorityP182high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
KEVITW
CISA Known Exploited Vulnerabilitydue 2021-11-17
Exploited in the wild
EPSS
19.91%
97.2th percentile
Windows Update Medic Service Elevation of Privilege Vulnerability
Affected
34 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | windows_10_1809 | < 10.0.17763.2114 | 10.0.17763.2114 |
| microsoft | windows_10_1909 | < 10.0.18363.1734 | 10.0.18363.1734 |
| microsoft | windows_10_2004 | < 10.0.19041.1165 | 10.0.19041.1165 |
| microsoft | windows_10_20h2 | < 10.0.19042.1165 | 10.0.19042.1165 |
| microsoft | windows_10_21h1 | < 10.0.19043.1165 | 10.0.19043.1165 |
| microsoft | windows_10_version_1809 | >= 10.0.0 < 10.0.17763.2114 | 10.0.17763.2114 |
| microsoft | windows_10_version_1909 | >= 10.0.0 < 10.0.18363.1734 | 10.0.18363.1734 |
| microsoft | windows_10_version_2004 | >= 10.0.0 < 10.0.19041.1165 | 10.0.19041.1165 |
| microsoft | windows_10_version_20h2 | >= 10.0.0 < 10.0.19042.1165 | 10.0.19042.1165 |
| microsoft | windows_10_version_21h1 | >= 10.0.0 < 10.0.19043.1165 | 10.0.19043.1165 |
| microsoft | windows_server_2004 | < 10.0.19041.1165 | 10.0.19041.1165 |
| microsoft | windows_server_2019 | < 10.0.17763.2114 | 10.0.17763.2114 |
| microsoft | windows_server_2019 | >= 10.0.0 < 10.0.17763.2114 | 10.0.17763.2114 |
| microsoft | windows_server_20h2 | < 10.0.19042.1165 | 10.0.19042.1165 |
| microsoft | windows_server_version_2004 | >= 10.0.0 < 10.0.19041.1165 | 10.0.19041.1165 |
| microsoft | windows_server_version_20h2 | >= 10.0.0 < 10.0.19042.1165 | 10.0.19042.1165 |
| msrc | windows_10_version_1809_for_32-bit_systems | — | — |
| msrc | windows_10_version_1809_for_arm64-based_systems | — | — |
| msrc | windows_10_version_1809_for_x64-based_systems | — | — |
| msrc | windows_10_version_1909_for_32-bit_systems | — | — |
| msrc | windows_10_version_1909_for_arm64-based_systems | — | — |
| msrc | windows_10_version_1909_for_x64-based_systems | — | — |
| msrc | windows_10_version_2004_for_32-bit_systems | — | — |
| msrc | windows_10_version_2004_for_arm64-based_systems | — | — |
| msrc | windows_10_version_2004_for_x64-based_systems | — | — |
Detection & IOCsextracted from sources · hover to see the quote
- →Check Point IPS blade signature available for detection of CVE-2021-36948 exploitation attempts targeting Windows Update Medic Service ↗
- →CVE-2021-36948 is actively exploited in the wild (confirmed by Microsoft); prioritize detection on Windows 10 and Windows Server 2019 systems where Update Medic Service runs ↗
- →CVE-2021-36948 is an elevation of privilege vulnerability; monitor for unexpected privilege escalation events (e.g., new admin accounts, cleared logs) on Windows 10 / Server 2019 hosts, particularly in ransomware attack chains ↗
- →No public exploit code was available at time of disclosure; exploitation was observed in the wild without public PoC, suggesting targeted/limited use — monitor for anomalous Windows Update Medic Service (WaaSMedicSvc) behavior ↗
- ·Patch KB5005030, KB5005031, and KB5005033 are the relevant remediation artifacts; absence of these KBs on Windows 10/Server 2019 hosts indicates a vulnerable and potentially exploitable state ↗
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv2.04.6MEDIUMAV:L/AC:L/Au:N/C:P/I:P/A:P
vulncheck7.8HIGH
cisa7.8HIGH
vendor_msrc7.8HIGH
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GHSA
GHSA-fcr2-qx8m-pfhp: Windows Update Medic Service Elevation of Privilege Vulnerability
ghsa_unreviewed·2022-05-24
CVE-2021-36948 [HIGH] CWE-269 GHSA-fcr2-qx8m-pfhp: Windows Update Medic Service Elevation of Privilege Vulnerability
Windows Update Medic Service Elevation of Privilege Vulnerability
Project0
The More You Know, The More You Know You Don’t Know - Project Zero
project_zero·2022-04-01
CVE-2016-4654 The More You Know, The More You Know You Don’t Know - Project Zero
A Year in Review of 0-days Used In-the-Wild in 2021
Posted by Maddie Stone, Google Project Zero
This is our third annual year in review of 0-days exploited in-the-wild [2020, 2019]. Each year we’ve looked back at all of the detected and disclosed in-the-wild 0-days as a group and synthesized what we think the trends and takeaways are. The goal of this report is not to detail each individual exploit, but instead to analyze the exploits from the year as a group, looking for trends, gaps, lessons learned, successes, etc. If you’re interested in the analysis of individual exploits, please check out our root cause analysis repository.
We perform and share this analysis in order to make 0-day hard. We want it to be more costly, more resource intensive, and overall more difficult for
VulnCheck
Microsoft Windows Update Medic Service Privilege Escalation Vulnerability
vulncheck·2021·CVSS 7.8
CVE-2021-36948 [HIGH] Microsoft Windows Update Medic Service Privilege Escalation Vulnerability
Microsoft Windows Update Medic Service Privilege Escalation Vulnerability
Microsoft Windows Update Medic Service contains an unspecified vulnerability that allows for privilege escalation.
Affected: Microsoft Windows
Required Action: Apply updates per vendor instructions.
Exploitation References: https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2021-Aug; https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit; https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json; https://www.microsoft.com/en-us/security/blog/2022/07/27/untangling-knotweed-european-private-sector-offensive-actor-using-0-day-exploits/; https://storage.googleapis.com/gweb-uniblog-publish-prod/documents/Buying_Spying_-_Insights_into_Commercial_Surveillance_Vendor
CISA
Microsoft Windows Update Medic Service Privilege Escalation Vulnerability
cisa·2021-11-03·CVSS 7.8
CVE-2021-36948 [HIGH] Microsoft Windows Update Medic Service Privilege Escalation Vulnerability
Vulnerability: Microsoft Windows Update Medic Service Privilege Escalation Vulnerability
Affected: Microsoft Windows
Microsoft Windows Update Medic Service contains an unspecified vulnerability that allows for privilege escalation.
Required Action: Apply updates per vendor instructions.
Notes: https://nvd.nist.gov/vuln/detail/CVE-2021-36948
Remediation Due Date: 2021-11-17
Microsoft
Windows Update Medic Service Elevation of Privilege Vulnerability
vendor_msrc·2021-08-10·CVSS 7.8
CVE-2021-36948 [HIGH] Windows Update Medic Service Elevation of Privilege Vulnerability
Windows Update Medic Service Elevation of Privilege Vulnerability
Windows Update: Windows Update
Microsoft: Microsoft
Impact: Elevation of Privilege
Exploit Status: Publicly Disclosed:No;Exploited:Yes;Latest Software Release:Exploitation Detected;Older Software Release:Exploitation Detected;DOS:N/A
Reference: https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5005030
Reference: https://support.microsoft.com/help/5005030
Reference: https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5005031
Reference: https://support.microsoft.com/help/5005031
Reference: https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5005033
Reference: https://support.microsoft.com/help/5005033
No detection rules found.
No public exploits indexed.
Qualys
Managing CISA Known Exploited Vulnerabilities with Qualys VMDR | Qualys
blogs_qualys·2022-02-23
Managing CISA Known Exploited Vulnerabilities with Qualys VMDR | Qualys
#### Table of Contents
- Situation
- Directive Scope
- CISA Catalog of Known Exploited Vulnerabilities
- Detect CISA Vulnerabilities Using Qualys VMDR
- CISA Exploited RTI
- Detailed Operational Dashboard
- Remediation
- Federal Enterprises and Agencies Can Act Now
- Summary
- Getting Started
CISA released a directive in November 2021, recommending urgent and prioritized remediation of actively exploited vulnerabilities. Both government agencies and corporations should heed this advice. This blog outlines how Qualys Vulnerability Management, Detection & Response can be used by any organization to respond to this directive efficiently and effectively.
## Situation
Last November 2021, the U.S. Cybersecurity and Infrastructure Security Agency (CISA) released a Binding Operational Directiv
Qualys
Qualys Response to CISA Alert: Binding Operational Directive 22-01
blogs_qualys·2021-11-09
Qualys Response to CISA Alert: Binding Operational Directive 22-01
## Table of Contents
Overview
Directive Scope
CISA Catalog of Known Exploited Vulnerabilities
Detect CISAs Vulnerabilities Using Qualys VMDR
Remediation
Federal Enterprises and Agencies Can Act Now
Summary
Getting Started
Start your VMDR 30-day, no-cost trial today
## Overview
On November 3, 2021, the U.S. Cybersecurity and Infrastructure Security Agency (CISA) released a Binding Operational Directive 22-01 , “Reducing the Significant Risk of Known Exploited Vulnerabilities.” This directive recommends urgent and prioritized remediation of the vulnerabilities that adversaries are actively exploiting. It establishes a CISA-managed catalog of known exploited vulnerabilities that carry significant risk to the federal government and establishes requirements for agencies to remediate
Qualys
Qualys Response to CISA Alert: Binding Operational Directive 22-01 | Qualys
blogs_qualys·2021-11-09
Qualys Response to CISA Alert: Binding Operational Directive 22-01 | Qualys
#### Table of Contents
- Overview
- Directive Scope
- CISA Catalog of Known Exploited Vulnerabilities
- Detect CISAs Vulnerabilities Using Qualys VMDR
- Remediation
- Federal Enterprises and Agencies Can Act Now
- Summary
- Getting Started
Start your VMDR 30-day, no-cost trial today
## Overview
On November 3, 2021, the U.S. Cybersecurity and Infrastructure Security Agency (CISA) released a Binding Operational Directive 22-01, “Reducing the Significant Risk of Known Exploited Vulnerabilities.” This directive recommends urgent and prioritized remediation of the vulnerabilities that adversaries are actively exploiting. It establishes a CISA-managed catalog of known exploited vulnerabilities that carry significant risk to the federal government and establishes requirements for agencies to
Checkpoint
16th August – Threat Intelligence Report
blogs_checkpoint·2021-08-16
CVE-2021-34473 16th August – Threat Intelligence Report
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## 16th August – Threat Intelligence Report
For the latest discoveries in cyber research for the week of 16th August, please download our Threat Intelligence Bulletin .
Top Attacks and Breaches
Check Point Research has revealed that the threat actor behinds last month’s cyber-attack on Iran’s train system is “Indra”, a group that identifies itself as Iranian regime opposition. They used similar tools in an attack against companies in Syria in 2019.
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Trendmicro
August Patch Tuesday: A Quiet Month for Microsoft
blogs_trendmicro·2021-08-11·CVSS 8.8
[HIGH] August Patch Tuesday: A Quiet Month for Microsoft
Exploits & Vulnerabilities
# August Patch Tuesday: A Quiet Month for Microsoft
August proves to be a quieter month for Microsoft, after an eventful July. This month, there were only 44 security bulletins, part of which are three Print Spooler flaws and a further fix for PetitPotam.
By: Trend Micro Research
2021/08/11
Read time: ( words)
Save to Folio
The August Patch Tuesday proves to be a calmer month for Microsoft, compared to the more eventful July security bulletin. This is evident in the short list of only 44 patched vulnerabilities published this month, of which seven are noted as critical and the rest as important. Eight were also submitted via the Trend Micro Zero Day Initiative.
What is notable for this month is the inclusion of three vulnerabilities in Print Spooler, given
Krebs
Microsoft Patch Tuesday, August 2021 Edition
blogs_krebs·2021-08-10·CVSS 7.8
CVE-2021-36948 [HIGH] Microsoft Patch Tuesday, August 2021 Edition
Microsoft today released software updates to plug at least 44 security vulnerabilities in its Windows operating systems and related products. The software giant warned that attackers already are pouncing on one of the flaws, which ironically enough involves an easy-to-exploit bug in the software component responsible for patching Windows 10 PCs and Windows Server 2019 machines.
Microsoft said attackers have seized upon CVE-2021-36948, which is a weakness in the Windows Update Medic service. Update Medic is a new service that lets users repair Windows Update components from a damaged state so that the device can continue to receive updates.
Redmond says while CVE-2021-36948 is being actively exploited, it is not aware of exploit code publicly available. The flaw is an “elevation of privil
Krebs
Microsoft Patch Tuesday, August 2021 Edition
blogs_krebs·2021-08-10·CVSS 7.8
CVE-2021-36948 [HIGH] Microsoft Patch Tuesday, August 2021 Edition
Microsoft today released software updates to plug at least 44 security vulnerabilities in its Windows operating systems and related products. The software giant warned that attackers already are pouncing on one of the flaws, which ironically enough involves an easy-to-exploit bug in the software component responsible for patching Windows 10 PCs and Windows Server 2019 machines.
Microsoft said attackers have seized upon CVE-2021-36948 , which is a weakness in the Windows Update Medic service. Update Medic is a new service that lets users repair Windows Update components from a damaged state so that the device can continue to receive updates.
Redmond says while CVE-2021-36948 is being actively exploited, it is not aware of exploit code publicly available. The flaw is an “elevation of privi
Tenable
Microsoft’s August 2021 Patch Tuesday Addresses 44 CVEs (CVE-2021-26424, CVE-2021-36948)
blogs_tenable·2021-08-10·CVSS 9.9
[CRITICAL] Microsoft’s August 2021 Patch Tuesday Addresses 44 CVEs (CVE-2021-26424, CVE-2021-36948)
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Qualys
Microsoft and Adobe Patch Tuesday (August 2021) - Microsoft 51 Vulnerabilities with 7 Critical, Adobe 29 Vulnerabilities | Qualys
blogs_qualys·2021-08-10·CVSS 8.8
CVE-2021-36942 [HIGH] Microsoft and Adobe Patch Tuesday (August 2021) - Microsoft 51 Vulnerabilities with 7 Critical, Adobe 29 Vulnerabilities | Qualys
### Microsoft Patch Tuesday – August 2021
Microsoft patched 51 vulnerabilities in their August 2021 Patch Tuesday release, and 7 of them are rated as critical severity. Three 0-day vulnerability patches were included in the release.
#### Critical Microsoft Vulnerabilities Patched
CVE-2021-36942 – Windows LSA Spoofing Vulnerability
An unauthenticated attacker could call a method on the LSARPC interface and coerce the domain controller to authenticate against another server using NTLM. A malicious user can use this attack to take complete control over windows domain Per Microsoft, this vulnerability affects all servers, but domain controllers should be prioritized in terms of applying security updates.
CVE-2021-34481 – Windows Print Spooler Remote Code Execution Vulnerability
A remote
Qualys
Microsoft and Adobe Patch Tuesday (August 2021) – Microsoft 51 Vulnerabilities with 7 Critical, Adobe 29 Vulnerabilities
blogs_qualys·2021-08-10·CVSS 7.0
CVE-2021-36942 [HIGH] Microsoft and Adobe Patch Tuesday (August 2021) – Microsoft 51 Vulnerabilities with 7 Critical, Adobe 29 Vulnerabilities
## Microsoft Patch Tuesday – August 2021
Microsoft patched 51 vulnerabilities in their August 2021 Patch Tuesday release, and 7 of them are rated as critical severity. Three 0-day vulnerability patches were included in the release.
## Critical Microsoft Vulnerabilities Patched
CVE-2021-36942 – Windows LSA Spoofing Vulnerability
An unauthenticated attacker could call a method on the LSARPC interface and coerce the domain controller to authenticate against another server using NTLM. A malicious user can use this attack to take complete control over windows domain Per Microsoft, this vulnerability affects all servers, but domain controllers should be prioritized in terms of applying security updates.
CVE-2021-34481 – Windows Print Spooler Remote Code Execution Vulnerability
A remote cod
Crowdstrike
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blogs_crowdstrike·CVSS 7.5
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Crowdstrike
August 2021 Patch Tuesday: Updates and Analysis
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STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
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How Charlotte AI AgentWorks Fuels Security's Agentic Ecosystem Mar 25, 2026
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Video Highlights the 4 Key Steps to Successful Incident Response Dec 02, 2019
Helping Non-Security Stakeholders Understand ATT&CK in 10 Minutes or Less [VI
2021-08-12
Published
2021-11-03
Added to CISA KEV
Exploited in the wild