CVE-2021-47457

Local denial of service via TX-buffer race

Published May 22, 2024 · Updated May 11, 2026

Race condition in the Linux kernel 5.10 through 5.10.75 and 5.11 through 5.14.14 allows local users to interrupt service via ISO-TP sockets. isotp_sendmsg() ignores an interrupted wait_event_interruptible() return, allowing a later sender to access the shared TX buffer while the prior transmission still owns it. A low-privileged local user must interrupt a blocking ISO-TP send while another sender enters the path; the resulting race can disrupt kernel availability.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux kernel 5.10 through 5.10.75 and 5.11 through 5.14.14 allows local users to interrupt service via ISO-TP sockets. isotp_sendmsg() ignores an interrupted wait_event_interruptible() return, allowing a later sender to access the shared TX buffer while the prior transmission still owns it. A low-privileged local user must interrupt a blocking ISO-TP send while another sender enters the path; the resulting race can disrupt kernel availability.

The record

CVE
CVE-2021-47457
Published
May 22, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-99, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 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=5.10
  2. Affected versionversion=e057dd3fc20ffb3d7f150af46542a51b59b90127 <053bc12df0d6097c1126d0e14fa778a0a8faeb64
  3. Affected versionversion=e057dd3fc20ffb3d7f150af46542a51b59b90127 <9acf636215a6ce9362fe618e7da4913b8bfe84c8
  4. Affected versionversion=e057dd3fc20ffb3d7f150af46542a51b59b90127 <a76abedd2be3926d6deba236a935c7f98abf9110

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=e057dd3fc20ffb3d7f150af46542a51b59b90127 <053bc12df0d6097c1126d0e14fa778a0a8faeb64; version=e057dd3fc20ffb3d7f150af46542a51b59b90127 <9acf636215a6ce9362fe618e7da4913b8bfe84c8; version=e057dd3fc20ffb3d7f150af46542a51b59b90127 <a76abedd2be3926d6deba236a935c7f98abf9110

Published CVSS scores

5.5CanonicalCVSS: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

CWE-99Improper Control of Resource Identifiers ('Resource Injection')
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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