CVE-2021-29264

System crash via negative receive fragment size

Published Mar 26, 2021 · Updated Aug 3, 2024

Denial of service in the Linux kernel through 5.11.10 allows local users to crash the system through the Freescale Gianfar Ethernet driver. In gfar_clean_rx_ring(), incorrect fragmented-frame accounting and FCS trimming allow the remaining receive size to wrap during an RX queue overrun. The path requires low-privilege local access, NAPI, jumbo packets, and a receive-queue overrun; the bounded consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.27%
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 through 5.11.10 allows local users to crash the system through the Freescale Gianfar Ethernet driver. In gfar_clean_rx_ring(), incorrect fragmented-frame accounting and FCS trimming allow the remaining receive size to wrap during an RX queue overrun. The path requires low-privilege local access, NAPI, jumbo packets, and a receive-queue overrun; the bounded consequence is a kernel crash.

The record

CVE
CVE-2021-29264
Published
Mar 26, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 26, 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

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.7NIST NVDAV:L/AC:M/Au:N/C:N/I:N/A:C
5.5NIST NVDCVSS: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

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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