CVE-2021-26896
published 2021-03-11CVE-2021-26896: Windows DNS Server Denial of Service Vulnerability
PriorityP338high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
7.85%
94.6th percentile
Windows DNS Server Denial of Service Vulnerability
Affected
24 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | windows_server_2008 | — | — |
| microsoft | windows_server_2008 | — | — |
| microsoft | windows_server_2008_r2_service_pack_1 | >= 6.1.7601.0 < 6.1.7601.24566 | 6.1.7601.24566 |
| microsoft | windows_server_2008_service_pack_2 | >= 6.0.6003.0 < 6.0.6003.21070 | 6.0.6003.21070 |
| microsoft | windows_server_2012 | — | — |
| microsoft | windows_server_2012 | >= 6.2.9200.0 < 6.2.9200.23298 | 6.2.9200.23298 |
| microsoft | windows_server_2012_r2 | >= 6.3.9600.0 < 6.3.9600.19968 | 6.3.9600.19968 |
| microsoft | windows_server_2016 | — | — |
| microsoft | windows_server_2016 | — | — |
| microsoft | windows_server_2016 | — | — |
| microsoft | windows_server_2016 | >= 10.0.14393.0 < 10.0.14393.4283 | 10.0.14393.4283 |
| microsoft | windows_server_2019 | >= 10.0.17763.0 < 10.0.17763.1817 | 10.0.17763.1817 |
| microsoft | windows_server_version_2004 | >= 10.0.0 < 10.0.19043.867 | 10.0.19043.867 |
| microsoft | windows_server_version_20h2 | >= 10.0.0 < 10.0.19043.867 | 10.0.19043.867 |
| msrc | windows_server_2008_for_32-bit_systems_service_pack_2 | — | — |
| msrc | windows_server_2008_for_x64-based_systems_service_pack_2 | — | — |
| msrc | windows_server_2008_r2_for_x64-based_systems_service_pack_1 | — | — |
| msrc | windows_server_2012 | — | — |
| msrc | windows_server_2012_r2 | — | — |
| msrc | windows_server_2016 | — | — |
| msrc | windows_server_2019 | — | — |
| msrc | windows_server_version_1909 | — | — |
| msrc | windows_server_version_2004 | — | — |
| msrc | windows_server_version_20h2 | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P
vendor_msrc7.5HIGH
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VulDB
Microsoft Windows Server 20H2 up to Server 2016 DNS Server denial of service
vuldb·2026-08-21·CVSS 7.5
CVE-2021-26896 [HIGH] Microsoft Windows Server 20H2 up to Server 2016 DNS Server denial of service
A vulnerability marked as critical has been reported in Microsoft Windows. This impacts an unknown function of the component DNS Server. The manipulation leads to denial of service.
This vulnerability is listed as CVE-2021-26896. The attack may be initiated remotely. There is no available exploit.
It is suggested to install a patch to address this issue.
GHSA
GHSA-fg89-fq65-83p5: Windows DNS Server Denial of Service Vulnerability This CVE ID is unique from CVE-2021-27063
ghsa_unreviewed·2022-05-24·CVSS 7.5
CVE-2021-26896 [HIGH] GHSA-fg89-fq65-83p5: Windows DNS Server Denial of Service Vulnerability This CVE ID is unique from CVE-2021-27063
Windows DNS Server Denial of Service Vulnerability This CVE ID is unique from CVE-2021-27063.
GHSA
GHSA-wvrr-f44c-x28v: Windows DNS Server Denial of Service Vulnerability This CVE ID is unique from CVE-2021-26896
ghsa_unreviewed·2022-05-24·CVSS 7.5
CVE-2021-27063 [HIGH] GHSA-wvrr-f44c-x28v: Windows DNS Server Denial of Service Vulnerability This CVE ID is unique from CVE-2021-26896
Windows DNS Server Denial of Service Vulnerability This CVE ID is unique from CVE-2021-26896.
Microsoft
Windows DNS Server Denial of Service Vulnerability
vendor_msrc·2021-03-09·CVSS 7.5
CVE-2021-26896 [HIGH] Windows DNS Server Denial of Service Vulnerability
Windows DNS Server Denial of Service Vulnerability
FAQ: Can this vulnerability by mitigated by enabling Secure Zone Updates?
Enabling Secure Zone Updates constrains the potential sources of the attack, but does not completely prevent it. For example, a malicious insider could attack a “secure zone update” DNS server from a domain-joined computer. This is only a partial mitigation.
Does this vulnerability impact just standalone DNS Primary Authoritative Server and not a DNS Server integrated with Active Directory?
This vulnerability impacts any DNS server. The surrounding configuration can limit possible vectors/sources for the attack, but proper mitigation requires this month’s security update patch.
FAQ: If my server is not configured to be a DNS server, it is vulnerable?
No, this vulne
No detection rules found.
No public exploits indexed.
Trendmicro
March Patch Tuesday: Fixes for Exchange Server, IE
blogs_trendmicro·2021-03-10·CVSS 9.1
[CRITICAL] March Patch Tuesday: Fixes for Exchange Server, IE
# March Patch Tuesday: Fixes for Exchange Server, IE
This month’s Patch Tuesday includes fixes already released for the Microsoft Exchange Server zero-day flaws attributed to Hafnium attacks.
By: Trend Micro
2021/03/10
Read time: ( words)
Save to Folio
This month’s Patch Tuesday features close to a hundred fixes, almost doubling last month’s total. The list includes patches already released for the Microsoft Exchange Server zero-day flaws attributed to Hafnium attacks.
Out of 89 patches released, 14 were rated Critical while the rest were deemed Important. Most of the critical vulnerabilities involve remote code execution (RCE) link except for an information disclosure bug. Fifteen of these were reported by the Zero Day Initiative (ZDI).
Microsoft Exchange Server Vulnerabilities
Th
Tenable
Microsoft’s March 2021 Patch Tuesday Addresses 82 CVEs (CVE-2021-26411)
blogs_tenable·2021-03-09·CVSS 8.8
[HIGH] Microsoft’s March 2021 Patch Tuesday Addresses 82 CVEs (CVE-2021-26411)
## Cloud Exposure
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## Vulnerability Exposure
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## AI Exposure
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## OT/IoT Exposure
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## Identity Exposure
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## Business needs
Active Directory
AI Security Posture Management (AI-SPM)
AWS security
Azure security
Cloud Security Posture Man
Talos
Microsoft Patch Tuesday for March 2021 — Snort rules and prominent vulnerabilities
blogs_talos·2021-03-09·CVSS 8.8
[HIGH] Microsoft Patch Tuesday for March 2021 — Snort rules and prominent vulnerabilities
By Jon Munshaw, with contributions from Nick Biasini.
Microsoft released its monthly security update Tuesday, disclosing 89 vulnerabilities across its suite of products, the most in any month so far this year.
There are 14 critical vulnerabilities as part of this release and one considered of “low” severity. The remainder are all “important.” Three of the critical vulnerabilities are the ones Microsoft disclosed last week in Exchange Server that the company said state-sponsored actors exploited in the wild to steal emails. Microsoft also announced Monday they were releasing patches for older versions of Exchange Server.
All organizations using the affected software should prevent external access to port 443 on Exchange Servers, or set up a VPN to provide external access to port 443. Thi
Talos
Microsoft Patch Tuesday for March 2021 — Snort rules and prominent vulnerabilities
blogs_talos·2021-03-09·CVSS 8.8
[HIGH] Microsoft Patch Tuesday for March 2021 — Snort rules and prominent vulnerabilities
## Microsoft Patch Tuesday for March 2021 — Snort rules and prominent vulnerabilities
By Jon Munshaw, with contributions from Nick Biasini.
Microsoft released its monthly security update Tuesday, disclosing 89 vulnerabilities across its suite of products, the most in any month so far this year.
There are 14 critical vulnerabilities as part of this release and one considered of “low” severity. The remainder are all “important.” Three of the critical vulnerabilities are the ones Microsoft disclosed last week in Exchange Server that the company said state-sponsored actors exploited in the wild to steal emails . Microsoft also announced Monday they were releasing patches for older versions of Exchange Server .
All organizations using the affected software should prevent external access to
2021-03-11
Published