CVE-2021-31185

Local service interruption through undisclosed mechanism

Published May 11, 2021 · Updated Aug 3, 2024

Denial of service in Windows Desktop Bridge on Windows 10 and Windows Server versions 2004 and 20H2 allows local users to interrupt service. Microsoft has not published the affected function or the operation that mishandles attacker-controlled input, so the concrete failure mechanism remains undisclosed. Exploitation requires local low-privilege access and no user interaction; the documented consequence is availability loss without data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.65%
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 Windows Desktop Bridge on Windows 10 and Windows Server versions 2004 and 20H2 allows local users to interrupt service. Microsoft has not published the affected function or the operation that mishandles attacker-controlled input, so the concrete failure mechanism remains undisclosed. Exploitation requires local low-privilege access and no user interaction; the documented consequence is availability loss without data disclosure or modification.

The record

CVE
CVE-2021-31185
Published
May 11, 2021
Updated
Aug 3, 2024
Vendor
Microsoft
Product
Windows Server, version 2004
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=10.0.0 <10.0.19041.982

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server, version 2004version=10.0.0 <10.0.19041.982
Microsoft · Windows 10 Version 20H2version=10.0.0 <10.0.19042.982
Microsoft · Windows Server version 20H2version=10.0.0 <10.0.19042.982
Microsoft · Windows 10 Version 2004version=10.0.0 <10.0.19041.982

Published CVSS scores

2.1NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.8MicrosoftCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
5.5MicrosoftCVSS:3.1/AV:L/AC:L/PR:L/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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