What’s Vulnerable › Vulnerabilities

CVE-2020-16894: Windows NAT Denial of Service Vulnerability

• Severity: medium (CVSS 6.8 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-10-16 · updated 2026-06-17

Description

<p>A denial of service vulnerability exists when Windows Network Address Translation (NAT) on a host server fails to properly validate input from a privileged user on a guest operating system. An attacker who successfully exploited the vulnerability could cause the host server to crash.</p> <p>To exploit the vulnerability, an attacker who already has a privileged account on a guest operating system, running as a virtual machine, could run a specially crafted application that causes a host machine to crash.</p> <p>The update addresses the vulnerability by modifying how Windows NAT accesses the host.</p>

Affected products

• Microsoft Windows 10 Version 1607: 1607
• Microsoft Windows Server 2016: all versions
• Microsoft Windows 10 1607: from 10.0.0 before publication — fixed in publication
• Microsoft Windows Server 2016: from 10.0.0 before publication — fixed in publication

How to fix

Upgrade to a fixed version: Microsoft Windows 10 1607 publication; Microsoft Windows Server 2016 publication. Check the vendor advisory for mitigations.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16894
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16894

Get alerted when CVE-2020-16894 or the next vulnerability affects your stack