What is CVE-2018-4307?

CVE-2018-4307 is a medium-severity vulnerability in Apple Iphone OS, classified under Improper Input Validation. CVSS score: 4.3/10. Published 2019-04-03.

How severe is CVE-2018-4307?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Is CVE-2018-4307 known to be exploited?

4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Improper input validation in Apple Iphone OS

CVE-2018-4307

A logic issue was addressed with improved state management. This issue affected versions prior to iOS 12, Safari 12.

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

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

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.011 (63.5th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 63.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Apple Iphone OS
Apple Safari
iOS, Safari — versions Versions prior to: iOS 12, Safari 12

Weakness classification (CWE)

CWE-20 — Improper Input Validation

Public proof-of-concept exploits

References

support.apple.com/kb/HT209106 (Vendor Advisory)
support.apple.com/kb/HT209109 (Vendor Advisory)

Frequently asked questions

What is CVE-2018-4307?: CVE-2018-4307 is a medium-severity vulnerability in Apple Iphone OS, classified under Improper Input Validation. CVSS score: 4.3/10. Published 2019-04-03.
How severe is CVE-2018-4307?: Medium severity. CVSS v3 base score is 4.3 out of 10.
Is CVE-2018-4307 known to be exploited?: 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.