What is CVE-2018-4399?

CVE-2018-4399 is a medium-severity vulnerability in Apple Iphone OS, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2019-04-03.

How severe is CVE-2018-4399?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Improper input validation in Apple Iphone OS

CVE-2018-4399

An access issue existed with privileged API calls. This issue was addressed with additional restrictions. This issue affected versions prior to iOS 12, macOS Mojave 10.14, tvOS 12, watchOS 5.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2019-04-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.009 (59.1th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Apple Iphone OS
Apple Mac OS X
Apple tvOS
Apple watchOS
iOS, macOS, tvOS, watchOS — versions Versions prior to: iOS 12, macOS Mojave 10.14, tvOS 12, watchOS 5

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

support.apple.com/kb/HT209107 (Vendor Advisory)
support.apple.com/kb/HT209193 (Vendor Advisory)
support.apple.com/kb/HT209106 (Vendor Advisory)
support.apple.com/kb/HT209139 (Vendor Advisory)
support.apple.com/kb/HT209108 (Vendor Advisory)

Frequently asked questions

What is CVE-2018-4399?: CVE-2018-4399 is a medium-severity vulnerability in Apple Iphone OS, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2019-04-03.
How severe is CVE-2018-4399?: Medium severity. CVSS v3 base score is 5.5 out of 10.