What is CVE-2020-3831?

CVE-2020-3831 is a high-severity vulnerability in Apple iOS, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2020-02-27.

How severe is CVE-2020-3831?

High severity. CVSS v3 base score is 7.0 out of 10.

Vulnerability in Apple iOS

CVE-2020-3831

A race condition was addressed with improved locking. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1. An application may be able to execute arbitrary code with kernel privileges.

Vulnerability class: Race Condition

Published 2020-02-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (55.0th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Apple iOS — versions unspecified
Apple Ipados
Apple Iphone OS

Weakness classification (CWE)

CWE-362 — Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition)

References

support.apple.com/HT210918 (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2020-3831?: CVE-2020-3831 is a high-severity vulnerability in Apple iOS, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.0/10. Published 2020-02-27.
How severe is CVE-2020-3831?: High severity. CVSS v3 base score is 7.0 out of 10.