CVE-2022-21911Network attack vector

Unauthenticated denial of service

Published Jan 11, 2022 · Updated Jan 2, 2025

Denial of service in Microsoft .NET Framework allows remote attackers to interrupt affected applications through unauthenticated network input. Microsoft has not published the affected component or the operation performed incorrectly on attacker-controlled input. Exploitation requires network reachability to an application that exposes the affected framework path and can terminate or become unavailable without reading or altering data.

CVSS severity7.5
High
EPSS probability3.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Microsoft .NET Framework allows remote attackers to interrupt affected applications through unauthenticated network input. Microsoft has not published the affected component or the operation performed incorrectly on attacker-controlled input. Exploitation requires network reachability to an application that exposes the affected framework path and can terminate or become unavailable without reading or altering data.

The record

CVE
CVE-2022-21911
Published
Jan 11, 2022
Updated
Jan 2, 2025
Vendor
Microsoft
Product
Microsoft .NET Framework 3.5 and 4.8
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Jan 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.8.0 <4.8.4465.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft .NET Framework 3.5 and 4.8version=4.8.0 <4.8.4465.0
Microsoft · Microsoft .NET Framework 2.0 Service Pack 2version=2.0.0 <2.0.50727.8955
Microsoft · Microsoft .NET Framework 3.5.1version=3.5.0 <2.0.50727.8955
Microsoft · Microsoft .NET Framework 3.5 and 4.7.2version=4.7.0 <4.7.3905.0
Microsoft · Microsoft .NET Frameworkversion=3.0.0.0 <10.0.14393.4886; version=4.0.0.0 <4.0.30319.36720; version=4.0.0.0 <4.7.3905.0
Microsoft · Microsoft .NET Framework 3.5version=3.5.0 <2.0.50727.8955
Microsoft · Microsoft .NET Framework 4.8version=4.8.0 <4.8.4465.0

Published CVSS scores

7.5Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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