CVE-2024-40994

Kernel memory corruption via PTP allocation overflow

Published Jul 12, 2024 · Updated May 11, 2026

Integer overflow in Linux kernel PTP code allows local users to corrupt kernel memory through an oversized max_vclocks value. The max_vclocks_store sysfs handler multiplies a user-controlled 32-bit count by sizeof(int) before kzalloc, so wraparound allocates less space than the following vclock-index copy requires. The path exists only on 32-bit systems with a physical PTP clock and local write access; resulting out-of-bounds kernel writes can crash the system or corrupt kernel data.

CVSS severity7.8
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Linux kernel PTP code allows local users to corrupt kernel memory through an oversized max_vclocks value. The max_vclocks_store sysfs handler multiplies a user-controlled 32-bit count by sizeof(int) before kzalloc, so wraparound allocates less space than the following vclock-index copy requires. The path exists only on 32-bit systems with a physical PTP clock and local write access; resulting out-of-bounds kernel writes can crash the system or corrupt kernel data.

The record

CVE
CVE-2024-40994
Published
Jul 12, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-190, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 12, 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=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <4b03da87d0b7074c93d9662c6e1a8939f9b8b86e
  2. Affected versionversion=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <666e934d749e50a37f3796caaf843a605f115b6f
  3. Affected versionversion=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <81d23d2a24012e448f651e007fac2cfd20a45ce0
  4. Affected versionversion=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <d50d62d5e6ee6aa03c00bddb91745d0b632d3b0f
  5. Affected versionversion=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <e1fccfb4638ee6188377867f6015d0ce35764a8e
  6. Affected versionversion=5.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <4b03da87d0b7074c93d9662c6e1a8939f9b8b86e; version=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <666e934d749e50a37f3796caaf843a605f115b6f; version=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <81d23d2a24012e448f651e007fac2cfd20a45ce0; version=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <d50d62d5e6ee6aa03c00bddb91745d0b632d3b0f; version=44c494c8e30e35713c7d11ca3c5ab332cbfabacf <e1fccfb4638ee6188377867f6015d0ce35764a8e; version=5.14

Published CVSS scores

7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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-190Integer Overflow or Wraparound
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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