CVE-2021-46941

System lockup via omitted USB controller resets

Published Feb 27, 2024 · Updated May 11, 2026

Denial of service in the Linux kernel DWC3 driver allows local users to lock up a system by switching a dual-role USB controller. The role-switch path changes GCTL.PrtCapDir without first asserting GCTL.CoreSoftReset and omits DCTL.CSftRst when entering device mode. Reachability requires local low-privileged access and hardware using the DWC3 dual-role controller; triggering the faulty transition can leave the host unresponsive.

CVSS severity5.5
Medium
EPSS probability0.22%
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 the Linux kernel DWC3 driver allows local users to lock up a system by switching a dual-role USB controller. The role-switch path changes GCTL.PrtCapDir without first asserting GCTL.CoreSoftReset and omits DCTL.CSftRst when entering device mode. Reachability requires local low-privileged access and hardware using the DWC3 dual-role controller; triggering the faulty transition can leave the host unresponsive.

The record

CVE
CVE-2021-46941
Published
Feb 27, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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.

  1. Affected versionversion=4.12
  2. Affected versionversion=41ce1456e1dbbc7355d0fcc10cf7c337c13def24 <1c10fd60c8595ea7ff7e29d3cf1fa88069941da3
  3. Affected versionversion=41ce1456e1dbbc7355d0fcc10cf7c337c13def24 <800f58217626c8b147aa40660e572ed8a0d56e3b
  4. Affected versionversion=41ce1456e1dbbc7355d0fcc10cf7c337c13def24 <f88359e1588b85cf0e8209ab7d6620085f3441d9
  5. Affected versionversion=41ce1456e1dbbc7355d0fcc10cf7c337c13def24 <fce7bbcd07d59ac30dba8ce225316b3b4c1c7b50

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.12; version=41ce1456e1dbbc7355d0fcc10cf7c337c13def24 <1c10fd60c8595ea7ff7e29d3cf1fa88069941da3; version=41ce1456e1dbbc7355d0fcc10cf7c337c13def24 <800f58217626c8b147aa40660e572ed8a0d56e3b; version=41ce1456e1dbbc7355d0fcc10cf7c337c13def24 <f88359e1588b85cf0e8209ab7d6620085f3441d9; version=41ce1456e1dbbc7355d0fcc10cf7c337c13def24 <fce7bbcd07d59ac30dba8ce225316b3b4c1c7b50

Published CVSS scores

5.5UbuntuCVSS: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.

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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

T1499Endpoint Denial of Service

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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