What is CVE-2018-4381?

CVE-2018-4381 is a medium-severity vulnerability in Apple iOS, classified under Uncontrolled Resource Consumption. CVSS score: 5.5/10. Published 2020-10-27.

How severe is CVE-2018-4381?

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

Resource exhaustion in Apple iOS

CVE-2018-4381

A resource exhaustion issue was addressed with improved input validation. This issue is fixed in tvOS 12.1, iOS 12.1. Processing a maliciously crafted message may lead to a denial of service.

Vulnerability class: DoS (Denial of Service)

Published 2020-10-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (47.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Apple iOS — versions unspecified
Apple Iphone OS
Apple tvOS — versions unspecified

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

support.apple.com/en-us/HT209192 (Vendor Advisory)
support.apple.com/en-us/HT209194 (Vendor Advisory)

Frequently asked questions

What is CVE-2018-4381?: CVE-2018-4381 is a medium-severity vulnerability in Apple iOS, classified under Uncontrolled Resource Consumption. CVSS score: 5.5/10. Published 2020-10-27.
How severe is CVE-2018-4381?: Medium severity. CVSS v3 base score is 5.5 out of 10.