CVE-2024-56716

Kernel crash via malformed netdevsim debugfs write

Published Dec 29, 2024 · Updated May 11, 2026

Improper input validation in Linux kernel netdevsim allows local users to crash the kernel through a zero-length or oversized debugfs write. The nsim_dev_health_break_write() handler failed to reject a zero count or a count larger than PAGE_SIZE before duplicating the buffer and indexing count minus one. Exploitation requires local access with netdevsim loaded and its writable break_health debugfs control exposed; the bounded consequence is a kernel crash.

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

Improper input validation in Linux kernel netdevsim allows local users to crash the kernel through a zero-length or oversized debugfs write. The nsim_dev_health_break_write() handler failed to reject a zero count or a count larger than PAGE_SIZE before duplicating the buffer and indexing count minus one. Exploitation requires local access with netdevsim loaded and its writable break_health debugfs control exposed; the bounded consequence is a kernel crash.

The record

CVE
CVE-2024-56716
Published
Dec 29, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-1284, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 29, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.5
  2. Affected versionversion=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <470c5ecbac2f19b1cdee2a6ce8d5650c3295c94b
  3. Affected versionversion=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <81bdfcd6e6a998e219c9dd49ec7291c2e0594bbc
  4. Affected versionversion=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <8e9ef6bdf71bf25f4735e0230ce1919de8985835
  5. Affected versionversion=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <b3a6daaf7cfb2de37b89fd7a5a2ad4ea9aa3e181
  6. Affected versionversion=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <d10321be26ff9e9e912697e9e8448099654ff561
  7. Affected versionversion=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <ee76746387f6233bdfa93d7406990f923641568f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.5; version=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <470c5ecbac2f19b1cdee2a6ce8d5650c3295c94b; version=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <81bdfcd6e6a998e219c9dd49ec7291c2e0594bbc; version=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <8e9ef6bdf71bf25f4735e0230ce1919de8985835; version=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <b3a6daaf7cfb2de37b89fd7a5a2ad4ea9aa3e181; version=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <d10321be26ff9e9e912697e9e8448099654ff561; version=82c93a87bf8bc0cdb5ec2ab99da7d87715ff889f <ee76746387f6233bdfa93d7406990f923641568f

Published CVSS scores

5.5CISA-ADPCVSS: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-1284Improper Validation of Specified Quantity in Input
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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