CVE-2021-47671

Availability degradation via leaked CAN error buffers

Published Apr 17, 2025 · Updated May 11, 2026

Memory leak in the Linux kernel 5.13 through 5.14.18 and 5.15 through 5.15.2 allows local users to degrade availability. In es58x_rx_err_msg(), a failed can->do_set_mode() call returns before netif_rx(skb), leaving the buffer from alloc_can_err_skb() unreleased. Triggering requires a locally accessible ETAS ES58x USB CAN adapter and a mode-setting failure; repeated failures consume kernel memory.

CVSS severity3.3
Low
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux kernel 5.13 through 5.14.18 and 5.15 through 5.15.2 allows local users to degrade availability. In es58x_rx_err_msg(), a failed can->do_set_mode() call returns before netif_rx(skb), leaving the buffer from alloc_can_err_skb() unreleased. Triggering requires a locally accessible ETAS ES58x USB CAN adapter and a mode-setting failure; repeated failures consume kernel memory.

The record

CVE
CVE-2021-47671
Published
Apr 17, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499.002
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 17, 2025CVE 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=5.13
  2. Affected versionversion=8537257874e949a59c834cecfd5a063e11b64b0b <4f389e1276a5389c92cef860c9fde8e1c802a871
  3. Affected versionversion=8537257874e949a59c834cecfd5a063e11b64b0b <7eb0881aec26099089f12ae850aebd93190b1dfe
  4. Affected versionversion=8537257874e949a59c834cecfd5a063e11b64b0b <d9447f768bc8c60623e4bb3ce65b8f4654d33a50

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.13; version=8537257874e949a59c834cecfd5a063e11b64b0b <4f389e1276a5389c92cef860c9fde8e1c802a871; version=8537257874e949a59c834cecfd5a063e11b64b0b <7eb0881aec26099089f12ae850aebd93190b1dfe; version=8537257874e949a59c834cecfd5a063e11b64b0b <d9447f768bc8c60623e4bb3ce65b8f4654d33a50

Published CVSS scores

6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
3.3CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
5.5SUSECVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.002Endpoint Denial of Service: Service Exhaustion Flood

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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