CVE-2018-4391

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-10-27 · updated 2026-06-17

Description

An inconsistent user interface issue was addressed with improved state management. This issue is fixed in macOS High Sierra 10.13.1, Security Update 2017-001 Sierra, and Security Update 2017-004 El Capitan, watchOS 4.3, iOS 12.1. Processing a maliciously crafted text message may lead to UI spoofing.

Affected products

Apple Iphone Os: before 12.1 — fixed in 12.1
macOS: from 10.13 before 10.13.1 — fixed in 10.13.1
Apple watchOS: before 4.3 — fixed in 4.3

How to fix

Upgrade to a fixed version: Apple Iphone Os 12.1; macOS 10.13.1; Apple watchOS 4.3. Check the vendor advisory for mitigations.

References

https://support.apple.com/en-us/HT208221
https://support.apple.com/en-us/HT208696
https://support.apple.com/en-us/HT209192
https://support.apple.com/en-us/HT208221
https://support.apple.com/en-us/HT208696
https://support.apple.com/en-us/HT209192

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