CVE-2023-40396

Kernel code execution via unsafe memory handling

Published Jul 29, 2024 · Updated Mar 19, 2025

Memory corruption in Apple IOUserEthernet before iOS 17, iPadOS 17, macOS 14, watchOS 10, and tvOS 17 allows local users to run kernel code. Apple discloses only that IOUserEthernet performs unsafe memory handling; the exact operation and attacker-controlled input path are not public. A locally installed app must reach the component, and successful exploitation grants kernel privileges on an affected device.

CVSS severity7.8
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Apple IOUserEthernet before iOS 17, iPadOS 17, macOS 14, watchOS 10, and tvOS 17 allows local users to run kernel code. Apple discloses only that IOUserEthernet performs unsafe memory handling; the exact operation and attacker-controlled input path are not public. A locally installed app must reach the component, and successful exploitation grants kernel privileges on an affected device.

The record

CVE
CVE-2023-40396
Published
Jul 29, 2024
Updated
Mar 19, 2025
Vendor
Apple
Product
iOS
Classifications
CWE-77, T1404, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 29, 2024CVE publishedPublication date reported by the CVE source.
  2. Mar 19, 2025Record 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=0 <17.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Apple · iOSversion=0 <17.0
Apple · iOS and iPadOSversion=unspecified <17
Apple · tvOSversion=unspecified <17
Apple · macOSversion=unspecified <14
Apple · iPadOSversion=0 <17.0
Apple · watchOSversion=unspecified <10

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8CISA-ADPCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1404Exploitation for Privilege Escalation
T1068Exploitation for Privilege Escalation

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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