CVE-2021-40449
Confirmed PUBLISHEDWin32k Elevation of Privilege Vulnerability
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
Win32k Elevation of Privilege Vulnerability
- CVE Published
- Oct 13, 2021
- Exploitation Reported
- Nov 17, 2021
- CVSS
- 7.8 High
- EPSS
- —
Affected Versions
27 version rows · page 2 of 2
| Vendor | Product | Version | Status |
|---|---|---|---|
| Microsoft |
Windows Server 2012 R2
|
6.3.0 to < 6.3.9600.20144 |
Affected |
| Microsoft |
Windows Server 2012 R2 (Server Core installation)
|
6.3.0 to < 6.3.9600.20144 |
Affected |
CVE References
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40449 portal.msrc.microsoft.com · CVE Record https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CV...
- packetstormsecurity.com/files/164926/Win32k-NtGdiResetDC-Use-After-F... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/164926/Win32k-NtGdiResetDC-Use-A...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2021-11-17 00:00 UTC |
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/local/cve_2021_40449.rb | Apr 28, 2025 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Exploitation Status
Exploited in the wild
Recorded 2021-11-17 00:00:00 UTC · CISA
Used in malware
Recorded 2021-11-17 00:00:00 UTC · CISA
Proof of concept available
Recorded 2021-10-20 09:24:36 UTC · GitHub
Weaknesses (CWE)
-
Use After Free
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/local/cve_2021_40449.rb | Apr 28, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2022-02-20 16:23:26 UTC · 9 stars
github · Created 2021-11-07 16:15:19 UTC · 52 stars
Exploit for CVE-2021-40449
github · Created 2021-10-25 04:58:49 UTC · 41 stars
LPE exploit for a UAF in Windows (CVE-2021-40449).
github · Created 2021-10-20 09:24:36 UTC · 96 stars
windows 10 14393 LPE
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
15:02 UTC about 1 year ago15:02 UTC · about 1 year ago
Metasploit module available
Exploit module available
-
00:00 UTC over 4 years ago00:00 UTC · over 4 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
00:00 UTC over 4 years ago00:00 UTC · over 4 years ago
First public exploitation report
Exploit observed in malware
-
09:24 UTC almost 5 years ago09:24 UTC · almost 5 years ago
Public PoC available
Public proof-of-concept code published
-
00:26 UTC almost 5 years ago00:26 UTC · almost 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC almost 5 years ago00:00 UTC · almost 5 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2021-40449
{
"cve_id": "CVE-2021-40449",
"title": "Win32k Elevation of Privilege Vulnerability",
"affected_vendor": "Microsoft",
"affected_product": "Windows 10 Version 1809, Windows Server 2019, Windows Server 2019 (Server Core installation), Windows 10 Version 1909, Windows 10 Version 21H1, Windows Server 2022, Windows 10 Version 2004, Windows Server version 2004, Windows 10 Version 20H2, Windows Server version 20H2, Windows 11 version 21H2, Windows 10 Version 1507, Windows 10 Version 1607, Windows Server 2016, Windows Server 2016 (Server Core installation), Windows 7, Windows 7 Service Pack 1, Windows 8.1, Windows Server 2008 Service Pack 2, Windows Server 2008 Service Pack 2 (Server Core installation), Windows Server 2008 Service Pack 2, Windows Server 2008 R2 Service Pack 1, Windows Server 2008 R2 Service Pack 1 (Server Core installation), Windows Server 2012, Windows Server 2012 (Server Core installation), Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation)",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 7.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}