CVE-2020-1228 — Windows DNS Denial of Service Vulnerability

Executive Summary

A denial of service vulnerability exists in Windows DNS when it fails to properly handle queries. An attacker who successfully exploited this vulnerability could cause the DNS service to become nonresponsive. To exploit the vulnerability, an authenticated attacker could send malicious DNS queries to a target, resulting in a denial of service. The update addresses the vulnerability by correcting how Windows DNS processes queries.

Overview

7.5

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Denial of Service

Released Sep 8 2020

Last Updated Sep 8 2020

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.04496 — 0.90262 percentile

NVD CVSS 7.5 HIGH — matches MSRC

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

0.04496

probability of exploitation in the next 30 days

0.90262 percentile - updated 2026-06-21

View on FIRST.org

Affected Products

7 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows Server 2008 for 32-bit Systems Service Pack 2 4577064 (Monthly Rollup) 4577070 (Security Only) Important Denial of Service 4571730 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577064 4577070 Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation) 4577064 (Monthly Rollup) 4577070 (Security Only) Important Denial of Service 4571730 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577064 4577070 Windows Server 2008 for x64-based Systems Service Pack 2 4577064 (Monthly Rollup) 4577070 (Security Only) Important Denial of Service 4571730 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577064 4577070 Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) 4577064 (Monthly Rollup) 4577070 (Security Only) Important Denial of Service 4571730 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577064 4577070 Windows Server 2008 R2 for x64-based Systems Service Pack 1 4577051 (Monthly Rollup) 4577053 (Security Only) Important Denial of Service 4571729 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577051 4577053 Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 4577051 (Monthly Rollup) 4577053 (Security Only) Important Denial of Service 4571729 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577051 4577053 Windows Server 2012 4577038 (Monthly Rollup) 4577048 (Security Only) Important Denial of Service 4571736 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577038 4577048 Windows Server 2012 (Server Core installation) 4577038 (Monthly Rollup) 4577048 (Security Only) Important Denial of Service 4571736 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577038 4577048 Windows Server 2012 R2 4577066 (Monthly Rollup) 4577071 (Security Only) Important Denial of Service 4571703 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577066 4577071 Windows Server 2012 R2 (Server Core installation) 4577066 (Monthly Rollup) 4577071 (Security Only) Important Denial of Service 4571703 Base: 7.5 Temporal: 6.7 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C Yes 4577066 4577071 Windows Server 2016	`4577015 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2016 (Server Core installation)	`4577015 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2019	`4570333 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2019 (Server Core installation)	`4570333 (Security Update)`	Important	Denial of Service	Yes
Windows Server, version 1903 (Server Core installation)	`4574727 (Security Update)`	Important	Denial of Service	Yes
Windows Server, version 1909 (Server Core installation)	`4574727 (Security Update)`	Important	Denial of Service	Yes
Windows Server, version 2004 (Server Core installation)	`4571756 (Security Update)`	Important	Denial of Service	Yes

Patches

4 patches

Article	Type	Restart
`4577015`	Security Update	Yes
`4570333`	Security Update	Yes
`4574727`	Security Update	Yes
`4571756`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

VictorV (Tang Tianwen), Quan Luo from Codesafe Team of Legendsec at Qi'anxin Group

References

MSRC Advisory MITRE NVD