High severity · published Oct 13, 2021
CVE-2021-40463
Windows Network Address Translation (NAT) Denial of Service Vulnerability
7.7
CVSS
2.6%
EPSS
No
On KEV
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)2.6% · higher than 85% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WI
Windows · Microsoft
20h2; 20h2; 20h2; 21h1; 21h1; 21h1; +11 more · source: NVD
W1
Windows 10 Version 1507 · Microsoft
10.0.0 before 10.0.10240.19086 · source: vendor
W1
Windows 10 Version 1607 · Microsoft
10.0.0 before 10.0.14393.4704 · source: vendor
W1
Windows 10 Version 1809 · Microsoft
10.0.0 before 10.0.17763.2237 · source: vendor
W1
Windows 10 Version 1909 · Microsoft
10.0.0 before 10.0.18363.1854 · source: vendor
W1
Windows 10 Version 2004 · Microsoft
10.0.0 before 10.0.19041.1288 · source: vendor
W1
Windows 10 Version 20H2 · Microsoft
10.0.0 before 10.0.19042.1288 · source: vendor
W1
Windows 10 Version 21H1 · Microsoft
10.0.0 before 10.0.19043.1288 · source: vendor
W1
Windows 11 version 21H2 · Microsoft
10.0.0 before 10.0.22000.258 · source: vendor
W8
Windows 8.1 · Microsoft
6.3.0 before 6.3.9600.20144 · source: vendor, NVD
WS
Windows Server 2012 · Microsoft
6.2.0 before 6.2.9200.23490 · source: vendor, NVD
WS
Windows Server 2012 (Server Core installation) · Microsoft
6.2.0 before 6.2.9200.23490 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-40463
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-40463
Patch
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40463
More from Windows
10.0
CVE-2020-1350
Microsoft Windows DNS Server Remote Code Execution Vulnerability
9.8
CVE-2025-59287
Windows Server Update Service (WSUS) Remote Code Execution Vulnerability
9.8
CVE-2019-0708
Microsoft Remote Desktop Services Remote Code Execution Vulnerability
9.8
CVE-2017-8543
Microsoft Windows Search Remote Code Execution Vulnerability
9.8
CVE-2008-4250
Microsoft Windows Buffer Overflow Vulnerability