Host denial of service via undisclosed DDA flaw
Published Nov 10, 2021 · Updated Aug 19, 2026
Denial of service in Microsoft Windows Hyper-V DDA allows low-privileged guest OS users to interrupt host availability through an assigned PCIe device. Microsoft has not published the defective DDA code path or the operation performed incorrectly on device-controlled input. Exploitation requires a DDA-capable Hyper-V host with a physical PCIe device assigned to a guest; the documented impact is limited to host availability.
Summary
What happened
Denial of service in Microsoft Windows Hyper-V DDA allows low-privileged guest OS users to interrupt host availability through an assigned PCIe device. Microsoft has not published the defective DDA code path or the operation performed incorrectly on device-controlled input. Exploitation requires a DDA-capable Hyper-V host with a physical PCIe device assigned to a guest; the documented impact is limited to host availability.
The record
- CVE
- CVE-2021-42274
- Published
- Nov 10, 2021
- Updated
- Aug 19, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- T1499
- Attack vector
- adjacent
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 10, 2021CVE publishedPublication date reported by the CVE source.
- Aug 19, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.2300
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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