Microsoft Windows
CVE-2020-16899 — Windows TCP/IP Denial of Service Vulnerability
Executive Summary
A denial of service vulnerability exists when the Windows TCP/IP stack improperly handles ICMPv6 Router Advertisement packets. An attacker who successfully exploited this vulnerability could cause a target system to stop responding. To exploit this vulnerability, an attacker would have to send specially crafted ICMPv6 Router Advertisement packets to a remote Windows computer. The vulnerability would not allow an attacker to execute code or to elevate user rights directly. The update addresses the vulnerability by correcting how the Windows TCP/IP stack handles ICMPv6 Router Advertisement packets.
Overview
7.5
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
More Likely
MS Exploit Likelihood
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
None
INTEGRITY
None
AVAILABILITY
High
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 6.7
EPSS Score
0.13454
probability of exploitation in the next 30 days
0.96092 percentile - updated 2026-08-14
View on FIRST.org
Affected Products
23 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Windows 10 Version 1709 for 32-bit Systems | 4580328 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1709 for ARM64-based Systems | 4580328 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1709 for x64-based Systems | 4580328 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1803 for 32-bit Systems | 4580330 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1803 for ARM64-based Systems | 4580330 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1803 for x64-based Systems | 4580330 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1809 for 32-bit Systems | 4577668 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1809 for ARM64-based Systems | 4577668 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1809 for x64-based Systems | 4577668 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1903 for 32-bit Systems | 4577671 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1903 for ARM64-based Systems | 4577671 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1903 for x64-based Systems | 4577671 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1909 for 32-bit Systems | 4577671 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1909 for ARM64-based Systems | 4577671 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 1909 for x64-based Systems | 4577671 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 2004 for 32-bit Systems | 4579311 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 2004 for ARM64-based Systems | 4579311 (Security Update) |
Important | Denial of Service | Yes |
| Windows 10 Version 2004 for x64-based Systems | 4579311 (Security Update) |
Important | Denial of Service | Yes |
| Windows Server 2019 | 4577668 (Security Update) |
Important | Denial of Service | Yes |
| Windows Server 2019 (Server Core installation) | 4577668 (Security Update) |
Important | Denial of Service | Yes |
| Windows Server, version 1903 (Server Core installation) | 4577671 (Security Update) |
Important | Denial of Service | Yes |
| Windows Server, version 1909 (Server Core installation) | 4577671 (Security Update) |
Important | Denial of Service | Yes |
| Windows Server, version 2004 (Server Core installation) | 4579311 (Security Update) |
Important | Denial of Service | Yes |
Patches
5 patches
| Article | Type | Restart |
|---|---|---|
4580328 |
Security Update | Yes |
4580330 |
Security Update | Yes |
4577668 |
Security Update | Yes |
4577671 |
Security Update | Yes |
4579311 |
Security Update | Yes |
Exploits & PoC
1 public PoCUnverified third-party code
Public proof-of-concept repositories aggregated from PoC-in-GitHub. They are not reviewed and may be incomplete, non-functional, or malicious — inspect the code before running anything.
| Repository | Stars | Published | Description |
|---|---|---|---|
| advanced-threat-research/CVE-2020-16899 | 20 | 2020-10-12 | CVE-2020-16899 - Microsoft Windows TCP/IP Vulnerability Detection Logic and Rule |
Detection Rules
No public Sigma or Nuclei detection rule has been mapped to this CVE yet. Coverage is concentrated on exploited / high-profile vulnerabilities; check SigmaHQ for updates.
Acknowledgments
Microsoft Platform Security Assurance & Vulnerability Research
References
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