Authenticated DNS service interruption
Published Jul 16, 2021 · Updated Aug 10, 2026
Denial of service in Microsoft Windows DNS Server allows remote authenticated users to interrupt the DNS service via network requests. Microsoft has not published the affected request type, parser, function, or erroneous operation within the DNS Server implementation. The target must run the DNS Server role and accept a request from an authenticated network user; exploitation interrupts name resolution without reported data access or modification.
Summary
What happened
Denial of service in Microsoft Windows DNS Server allows remote authenticated users to interrupt the DNS service via network requests. Microsoft has not published the affected request type, parser, function, or erroneous operation within the DNS Server implementation. The target must run the DNS Server role and accept a request from an authenticated network user; exploitation interrupts name resolution without reported data access or modification.
The record
- CVE
- CVE-2021-34444
- Published
- Jul 16, 2021
- Updated
- Aug 10, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 16, 2021CVE publishedPublication date reported by the CVE source.
- Aug 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=10.0.17763.0 <10.0.17763.2061
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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