What is CVE-2018-4344?

CVE-2018-4344 is a high-severity vulnerability in Apple Iphone OS, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.8/10. Published 2019-04-03.

How severe is CVE-2018-4344?

High severity. CVSS v3 base score is 7.8 out of 10.

Is CVE-2018-4344 known to be exploited?

Yes. CVE-2018-4344 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-06-27), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.

Buffer overflow in Apple Iphone OS

CVE-2018-4344

A memory corruption issue was addressed with improved memory handling. This issue affected versions prior to iOS 12, macOS Mojave 10.14, tvOS 12, watchOS 5.

Vulnerability class: Buffer Overflow

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

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.024 (83.6th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 83.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.029 · newest: 0.024 · change: -0.005

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-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2022-06-27. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-07-18.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

support.apple.com/kb/HT209107 (Release Notes, Vendor Advisory)
support.apple.com/kb/HT209106 (Release Notes, Vendor Advisory)
support.apple.com/kb/HT209139 (Release Notes, Vendor Advisory)
support.apple.com/kb/HT209108 (Release Notes, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2018-4344?: CVE-2018-4344 is a high-severity vulnerability in Apple Iphone OS, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.8/10. Published 2019-04-03.
How severe is CVE-2018-4344?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2018-4344 known to be exploited?: Yes. CVE-2018-4344 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-06-27), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.