CVE-2021-47224

Service interruption via premature SKB release

Published May 21, 2024 · Updated Aug 5, 2026

Use-after-free in the Linux ll_temac driver from 2.6.31 allows local users to interrupt service by transmitting fragmented packets. The TX completion path attaches the skb pointer to the first buffer descriptor and frees it before later descriptors finish DMA processing. Exploitation requires the Xilinx ll_temac driver and a multi-descriptor transmit packet; the documented consequence is limited to system availability.

CVSS severity6.2
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux ll_temac driver from 2.6.31 allows local users to interrupt service by transmitting fragmented packets. The TX completion path attaches the skb pointer to the first buffer descriptor and frees it before later descriptors finish DMA processing. Exploitation requires the Xilinx ll_temac driver and a multi-descriptor transmit packet; the documented consequence is limited to system availability.

The record

CVE
CVE-2021-47224
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=2.6.31
  2. Affected versionversion=92744989533cbe85e8057935d230e128810168ce <019ab7d044d0ebf97e1236bb8935b7809be92358
  3. Affected versionversion=92744989533cbe85e8057935d230e128810168ce <6aa32217a9a446275440ee8724b1ecaf1838df47
  4. Affected versionversion=92744989533cbe85e8057935d230e128810168ce <6d120ab4dc39a543c6b63361e1d0541c382900a3
  5. Affected versionversion=92744989533cbe85e8057935d230e128810168ce <e8afe05bd359ebe12a61dbdc94c06c00ea3e8d4b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.31; version=92744989533cbe85e8057935d230e128810168ce <019ab7d044d0ebf97e1236bb8935b7809be92358; version=92744989533cbe85e8057935d230e128810168ce <6aa32217a9a446275440ee8724b1ecaf1838df47; version=92744989533cbe85e8057935d230e128810168ce <6d120ab4dc39a543c6b63361e1d0541c382900a3; version=92744989533cbe85e8057935d230e128810168ce <e8afe05bd359ebe12a61dbdc94c06c00ea3e8d4b

Published CVSS scores

6.2CISA-ADPCVSS:3.1/AV:L/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
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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