CVE-2018-4391

Name: CVE-2018-4391
Creator: NVD / NIST
Published: 2020-10-27T20:15:13.563+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.85%

Last modified Jun 17, 2026

CVE-2018-4391 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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. EPSS estimates a 0.85% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS Probability

0.85%

53.7th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Apple	Iphone Os	< 12.1
Apple	Mac Os X	>= 10.13, < 10.13.1
Apple	Watchos	< 4.3

References

https://support.apple.com/en-us/HT208221Vendor Advisory
https://support.apple.com/en-us/HT208696Vendor Advisory
https://support.apple.com/en-us/HT209192Vendor Advisory
https://support.apple.com/en-us/HT208221Vendor Advisory
https://support.apple.com/en-us/HT208696Vendor Advisory
https://support.apple.com/en-us/HT209192Vendor Advisory

Timeline

Published: Oct 27, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-4391?

How severe is CVE-2018-4391?

CVE-2018-4391 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.85% probability of exploitation in the next 30 days.

How do I fix CVE-2018-4391?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-4391?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST