CVE-2021-33739
published 2021-06-08CVE-2021-33739: Microsoft DWM Core Library Elevation of Privilege Vulnerability
PriorityP279high7.8CVSS 3.1
AVLACLPRNUIRSUCHIHAH
KEVITWEXPLOIT
CISA Known Exploited Vulnerabilitydue 2021-11-17
Exploited in the wild
EPSS
6.55%
93.0th percentile
Microsoft DWM Core Library Elevation of Privilege Vulnerability
Affected
25 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | windows_10_1909 | < 10.0.18363.1621 | 10.0.18363.1621 |
| microsoft | windows_10_2004 | < 10.0.19041.1052 | 10.0.19041.1052 |
| microsoft | windows_10_20h2 | < 10.0.19042.1052 | 10.0.19042.1052 |
| microsoft | windows_10_21h1 | < 10.0.19043.1052 | 10.0.19043.1052 |
| microsoft | windows_10_version_1909 | >= 10.0.0 < 10.0.18363.1621 | 10.0.18363.1621 |
| microsoft | windows_10_version_2004 | >= 10.0.0 < 10.0.19041.1052 | 10.0.19041.1052 |
| microsoft | windows_10_version_20h2 | >= 10.0.0 < 10.0.19042.1052 | 10.0.19042.1052 |
| microsoft | windows_10_version_21h1 | >= 10.0.0 < 10.0.19043.1052 | 10.0.19043.1052 |
| microsoft | windows_server_2004 | < 10.0.19041.1052 | 10.0.19041.1052 |
| microsoft | windows_server_20h2 | < 10.0.19042.1052 | 10.0.19042.1052 |
| microsoft | windows_server_version_2004 | >= 10.0.0 < 10.0.19041.1052 | 10.0.19041.1052 |
| microsoft | windows_server_version_20h2 | >= 10.0.0 < 10.0.19042.1052 | 10.0.19042.1052 |
| 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 | — | — |
| msrc | windows_10_version_20h2_for_32-bit_systems | — | — |
| msrc | windows_10_version_20h2_for_arm64-based_systems | — | — |
| msrc | windows_10_version_21h1_for_32-bit_systems | — | — |
| msrc | windows_10_version_21h1_for_arm64-based_systems | — | — |
| msrc | windows_10_version_21h1_for_x64-based_systems | — | — |
| msrc | windows_server_version_2004 | — | — |
| msrc | windows_server_version_20h2 | — | — |
Detection & IOCsextracted from sources · hover to see the quote
- →CVE-2021-33739 is a local privilege escalation in Windows DWM Core Library that has been actively exploited in the wild. Monitor for suspicious processes spawning with elevated privileges after executing a local binary or script. ↗
- →Exploitation has been detected on both latest and older software releases. Treat any unexplained privilege escalation on Windows DWM-related processes as a high-priority alert. ↗
- →Initial access vector may be phishing — monitor for users executing email attachments (executables) that subsequently trigger DWM-related privilege escalation. ↗
- ·This is a local privilege escalation only — remote exploitation is not indicated. Detection focus should be on post-access activity on the local host, not network-based indicators. ↗
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv2.04.6MEDIUMAV:L/AC:L/Au:N/C:P/I:P/A:P
vulncheck8.4HIGH
cisa7.8HIGH
vendor_msrc8.4HIGH
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CISA
Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
cisa·2021-11-03·CVSS 7.8
CVE-2021-33739 [HIGH] Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
Vulnerability: Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
Affected: Microsoft Windows
Microsoft Desktop Window Manager (DWM) Core Library contains an unspecified vulnerability that allows for privilege escalation.
Required Action: Apply updates per vendor instructions.
Notes: https://nvd.nist.gov/vuln/detail/CVE-2021-33739
Remediation Due Date: 2021-11-17
Microsoft
Microsoft DWM Core Library Elevation of Privilege Vulnerability
vendor_msrc·2021-06-08·CVSS 8.4
CVE-2021-33739 [HIGH] Microsoft DWM Core Library Elevation of Privilege Vulnerability
Microsoft DWM Core Library Elevation of Privilege Vulnerability
FAQ: How could an attacker exploit this vulnerability?
This vulnerability is subject to a local escalation of privilege attack. The attacker would most likely arrange to run an executable or script on the local computer. An attacker could gain access to the computer through a variety of methods, such as via a phishing attack where a user clicks an executable file that is attached to an email.
Windows DWM Core Library: Windows DWM Core Library
Microsoft: Microsoft
Impact: Elevation of Privilege
Exploit Status: Publicly Disclosed:Yes;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=KB5003635
GHSA
GHSA-4mwq-m8xw-34mr: Microsoft DWM Core Library Elevation of Privilege Vulnerability
ghsa_unreviewed·2022-05-24
CVE-2021-33739 [HIGH] CWE-269 GHSA-4mwq-m8xw-34mr: Microsoft DWM Core Library Elevation of Privilege Vulnerability
Microsoft DWM Core Library Elevation of Privilege Vulnerability
VulnCheck
Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
vulncheck·2021·CVSS 8.4
CVE-2021-33739 [HIGH] Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
Microsoft Desktop Window Manager (DWM) Core Library Privilege Escalation Vulnerability
Microsoft Desktop Window Manager (DWM) Core Library 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-Jun; https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json
Exploit PoC: https://vulncheck.com/xdb/31ac107a9305; https://vulncheck.com/xdb/668bbacf64d2; https://vulncheck.com/xdb/afe35658a490
Remediation Due: 2021-11-17
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
Krebs
Microsoft Patches Six Zero-Day Security Holes
blogs_krebs·2021-06-08·CVSS 5.2
[MEDIUM] Microsoft Patches Six Zero-Day Security Holes
Microsoft today released another round of security updates for Windows operating systems and supported software, including fixes for six zero-day bugs that malicious hackers already are exploiting in active attacks.
June’s Patch Tuesday addresses just 49 security holes — about half the normal number of vulnerabilities lately. But what this month lacks in volume it makes up for in urgency: Microsoft warns that bad guys are leveraging a half-dozen of those weaknesses to break into computers in targeted attacks.
Among the zero-days are:
–CVE-2021-33742, a remote code execution bug in a Windows HTML component.
–CVE-2021-31955, an information disclosure bug in the Windows Kernel
–CVE-2021-31956, an elevation of privilege flaw in Windows NTFS
–CVE-2021-33739, an elevation of privilege flaw
Qualys
Microsoft & Adobe Patch Tuesday (June 2021) – Microsoft 50 Vulnerabilities with 5 Critical, Adobe 21 Critical Vulnerabilities | Qualys
blogs_qualys·2021-06-08·CVSS 5.2
CVE-2021-31985 [MEDIUM] Microsoft & Adobe Patch Tuesday (June 2021) – Microsoft 50 Vulnerabilities with 5 Critical, Adobe 21 Critical Vulnerabilities | Qualys
### Microsoft Patch Tuesday – June 2021
Microsoft patched 50 CVEs in their June 2021 Patch Tuesday release, and five of them are rated as critical severity. Six have applicable exploits.
#### Critical Microsoft Vulnerabilities Patched
CVE-2021-31985 – Microsoft Defender Remote Code Execution Vulnerability
Microsoft released patches addressing a critical RCE vulnerability in its Defender product (CVE-2021-31985). This CVE has a high likelihood of exploitability and is assigned a CVSSv3 base score of 7.8 by the vendor.
CVE-2021-31959 – Scripting Engine Memory Corruption Vulnerability
Microsoft released patches addressing a critical memory corruption vulnerability in the Chakra JScript scripting engine. This vulnerability impacts Windows RT, Windows 7, Windows 8, Windows 10, Windows Ser
Talos
Microsoft Patch Tuesday for June 2021 — Snort rules and prominent vulnerabilities
blogs_talos·2021-06-08·CVSS 8.8
[HIGH] Microsoft Patch Tuesday for June 2021 — Snort rules and prominent vulnerabilities
By Jon Munshaw, with contributions from Edmund Brumaghin.
Microsoft released its monthly security update Tuesday, disclosing 51 vulnerabilities across its suite of products, breaking last month’s 16-month record of the fewest vulnerabilities disclosed in a month by the company.
There are only four critical vulnerabilities patched in this month, while all the other ones are considered “important.” However, there are several vulnerabilities that Microsoft states are being actively exploited in the wild.
This month’s security update provides updates for several pieces of software and Windows functions, including SharePoint Server, the Windows kernel and Outlook. For a full rundown of these CVEs, head to Microsoft’s security update page. Two of the vulnerabilities Microsoft disclosed today
Tenable
Microsoft’s June 2021 Patch Tuesday Addresses 49 CVEs (CVE-2021-31955, CVE-2021-31956 and CVE-2021-33742)
blogs_tenable·2021-06-08·CVSS 5.5
[MEDIUM] Microsoft’s June 2021 Patch Tuesday Addresses 49 CVEs (CVE-2021-31955, CVE-2021-31956 and CVE-2021-33742)
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## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Talos
Microsoft Patch Tuesday for June 2021 — Snort rules and prominent vulnerabilities
blogs_talos·2021-06-08·CVSS 8.8
[HIGH] Microsoft Patch Tuesday for June 2021 — Snort rules and prominent vulnerabilities
## Microsoft Patch Tuesday for June 2021 — Snort rules and prominent vulnerabilities
By Jon Munshaw, with contributions from Edmund Brumaghin.
Microsoft released its monthly security update Tuesday, disclosing 51 vulnerabilities across its suite of products, breaking last month’s 16-month record of the fewest vulnerabilities disclosed in a month by the company.
There are only four critical vulnerabilities patched in this month, while all the other ones are considered “important.” However, there are several vulnerabilities that Microsoft states are being actively exploited in the wild.
This month’s security update provides updates for several pieces of software and Windows functions, including SharePoint Server, the Windows kernel and Outlook. For a full rundown of these CVEs, head to M
Qualys
Microsoft & Adobe Patch Tuesday (June 2021) – Microsoft 50 Vulnerabilities with 5 Critical, Adobe 21 Critical Vulnerabilities
blogs_qualys·2021-06-08·CVSS 5.2
CVE-2021-31985 [MEDIUM] Microsoft & Adobe Patch Tuesday (June 2021) – Microsoft 50 Vulnerabilities with 5 Critical, Adobe 21 Critical Vulnerabilities
## Microsoft Patch Tuesday – June 2021
Microsoft patched 50 CVEs in their June 2021 Patch Tuesday release, and five of them are rated as critical severity. Six have applicable exploits.
## Critical Microsoft Vulnerabilities Patched
CVE-2021-31985 – Microsoft Defender Remote Code Execution Vulnerability
Microsoft released patches addressing a critical RCE vulnerability in its Defender product (CVE-2021-31985). This CVE has a high likelihood of exploitability and is assigned a CVSSv3 base score of 7.8 by the vendor.
CVE-2021-31959 – Scripting Engine Memory Corruption Vulnerability
Microsoft released patches addressing a critical memory corruption vulnerability in the Chakra JScript scripting engine. This vulnerability impacts Windows RT, Windows 7, Windows 8, Windows 10, Windows Server
Krebs
Microsoft Patches Six Zero-Day Security Holes
blogs_krebs·2021-06-08·CVSS 5.2
[MEDIUM] Microsoft Patches Six Zero-Day Security Holes
Microsoft today released another round of security updates for Windows operating systems and supported software, including fixes for six zero-day bugs that malicious hackers already are exploiting in active attacks.
June’s Patch Tuesday addresses just 49 security holes — about half the normal number of vulnerabilities lately. But what this month lacks in volume it makes up for in urgency: Microsoft warns that bad guys are leveraging a half-dozen of those weaknesses to break into computers in targeted attacks.
Among the zero-days are:
– CVE-2021-33742 , a remote code execution bug in a Windows HTML component.
– CVE-2021-31955 , an information disclosure bug in the Windows Kernel
– CVE-2021-31956 , an elevation of privilege flaw in Windows NTFS
– CVE-2021-33739 , an elevation of privilege
Crowdstrike
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Video Highlights the 4 Key Steps to Successful Incident Response Dec 02, 2019
Helping Non-Security Stakeholders Understand AT
Crowdstrike
Patch Tuesday 2021: A Vulnerability Deep Dive
blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] Patch Tuesday 2021: A Vulnerability Deep Dive
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Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
How Charlotte AI AgentWorks Fuels Security's Agentic Ecosystem Mar 25, 2026
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
Crowdstrike
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blogs_crowdstrike·CVSS 7.5
CVE-2026-20929 [HIGH] June 2021 Patch Tuesday: Updates and Analysis
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
Falcon for IT Supports Windows Secure Boot Certificate Lifecycle Management Apr 01, 2026
Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
How Charlotte AI AgentWorks Fuels Security's Agentic Ecosystem Mar 25, 2026
STARDUST CHOLLIMA Likely Compromises Axios npm Package Apr 01, 2026
Falcon for IT Supports Windows Secure Boot Certificate Lifecycle Management Apr 01, 2026
Detecting CVE-2026-20929: Kerberos Authentication Relay via CNAME Abuse Mar 31, 2026
How Charlotte AI AgentWorks Fuels Security's Agentic Ecosystem Mar 25, 2026
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
2021-06-08
Published
2021-11-03
Added to CISA KEV
Exploited in the wild