CVE-2021-40449Win32k Elevation of Privilege Vulnerability
- 7.8HighCVSS base score
- 81.9%Exploitation in 30 daysEPSS · top 0.3% of all CVEs
- YesKnown exploitedin CISA's KEV since 17 Nov 2021
- 1Public exploitsMetasploit, Nuclei and Exploit-DB
Description
Win32k Elevation of Privilege Vulnerability
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Microsoft Windows Win32k Privilege Escalation Vulnerability.
- Added
- 17 Nov 2021
- Fix due (US federal)
- 1 Dec 2021
- Used by ransomware
- Known
Apply updates per vendor instructions.
ENISA's EU Vulnerability Database lists it as exploited, from CISA's KEV, since 17 Nov 2021.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Metasploit module for it. CISA's SSVC rates its exploitation: it is being exploited.
Show the exploits1
Metasploit modules1 module
- Win32k NtGdiResetDC Use After Free Local Privilege Elevation (Metasploit module) (opens in a new tab)
exploit/windows/local/cve_2021_40449Rank gooddisclosed 12 Oct 2021
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By microsoft
- 41 days later
· 41 days later
Published
- 35 days later
· 35 days later
Added to CISA KEV
Known exploited, also by ransomware
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| microsoftCNA (assigner) | 3.1 | High7.8 | 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 |
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 81.9% · top 0.3% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
Microsoft · Windows 10 Version 1809
- affected 10.0.0 – < 10.0.17763.2237
Microsoft · Windows Server 2019
- affected 10.0.0 – < 10.0.17763.2237
Microsoft · Windows Server 2019 (Server Core installation)
- affected 10.0.0 – < 10.0.17763.2237
Microsoft · Windows 10 Version 1909
- affected 10.0.0 – < 10.0.18363.1854
Microsoft · Windows 10 Version 21H1
- affected 10.0.0 – < 10.0.19041.1288
Microsoft · Windows Server 2022
- affected 10.0.0 – < 10.0.20348.288
Microsoft · Windows 10 Version 2004
- affected 10.0.0 – < 10.0.19041.1288
Microsoft · Windows Server version 2004
- affected 10.0.0 – < 10.0.19041.1288
Microsoft · Windows 10 Version 20H2
- affected 10.0.0 – < 10.0.19041.1288
Microsoft · Windows Server version 20H2
- affected 10.0.0 – < 10.0.19042.1288
Microsoft · Windows 11 version 21H2
- affected 10.0.0 – < 10.0.22000.258
Microsoft · Windows 10 Version 1507
- affected 10.0.0 – < 10.0.10240.19086
Microsoft · Windows 10 Version 1607
- affected 10.0.0 – < 10.0.14393.4704
Microsoft · Windows Server 2016
- affected 10.0.0 – < 10.0.14393.4704
Microsoft · Windows Server 2016 (Server Core installation)
- affected 10.0.0 – < 10.0.14393.4704
- affected 6.1.0 – < 6.1.7601.25740
Microsoft · Windows 7 Service Pack 1
- affected 6.1.0 – < 6.1.7601.25740
- affected 6.3.0 – < 6.3.9600.20144
Microsoft · Windows Server 2008 Service Pack 2
- affected 6.0.0 – < 6.0.6003.21251
Microsoft · Windows Server 2008 Service Pack 2 (Server Core installation)
- affected 6.0.0 – < 6.0.6003.21251
Microsoft · Windows Server 2008 Service Pack 2
- affected 6.0.0 – < 6.0.6003.21251
Microsoft · Windows Server 2008 R2 Service Pack 1
- affected 6.1.0 – < 6.1.7601.25740
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)
- affected 6.0.0 – < 6.1.7601.25740
Microsoft · Windows Server 2012
- affected 6.2.0 – < 6.2.9200.23490
Microsoft · Windows Server 2012 (Server Core installation)
- affected 6.2.0 – < 6.2.9200.23490
Microsoft · Windows Server 2012 R2
- affected 6.3.0 – < 6.3.9600.20144
Microsoft · Windows Server 2012 R2 (Server Core installation)
- affected 6.3.0 – < 6.3.9600.20144
References
References3
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40449 (opens in a new tab)x_refsource_MISCx_transferred
- http://packetstormsecurity.com/files/164926/Win32k-NtGdiResetDC-Use-After-Free-Local-Privilege-Escalation.html (opens in a new tab)x_refsource_MISCx_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40449 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-27626 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-40449)Record last updated .