CVE-2018-4478

Physical privilege escalation via EFI validation failure

Published Dec 23, 2021 · Updated Aug 5, 2024

Improper validation in EFI in Apple macOS allows physically proximate attackers to elevate privileges on an affected device. EFI accepts an unspecified invalid condition because its validation logic is incomplete; Apple has not disclosed the checked object or operation. The flaw affects High Sierra 10.13.4, Sierra 10.12.6, and OS X El Capitan 10.11.6 and requires physical access.

CVSS severity6.8
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

Improper validation in EFI in Apple macOS allows physically proximate attackers to elevate privileges on an affected device. EFI accepts an unspecified invalid condition because its validation logic is incomplete; Apple has not disclosed the checked object or operation. The flaw affects High Sierra 10.13.4, Sierra 10.12.6, and OS X El Capitan 10.11.6 and requires physical access.

The record

CVE
CVE-2018-4478
Published
Dec 23, 2021
Updated
Aug 5, 2024
Vendor
Apple
Product
macOS
Classifications
CWE-269, T1068
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

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

  1. Affected versionversion=unspecified <10.13

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Apple · macOSversion=unspecified <10.13

Published CVSS scores

6.8NIST NVDCVSS:3.1/AV:P/AC:L/PR:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
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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