What is CVE-2020-3837?

CVE-2020-3837 is a high-severity vulnerability in Apple iOS, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2020-02-27.

How severe is CVE-2020-3837?

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

Is CVE-2020-3837 known to be exploited?

Yes. CVE-2020-3837 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-06-27), indicating it is being actively exploited. 5 public proof-of-concept repositories are indexed.

Buffer overflow in Apple iOS

CVE-2020-3837

A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS 6.1.2. An application may be able to execute arbitrary code with kernel privileges.

Vulnerability class: Buffer Overflow

Published 2020-02-27 · 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: 0.148 (96.7th percentile), scored 2026-10-18.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 96.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.161 · newest: 0.148 · change: -0.013

Affected products

Apple iOS — versions unspecified
Apple Ipados
Apple Iphone OS
Apple macOS — versions unspecified
Apple Mac OS X
Apple tvOS — versions unspecified
Apple watchOS — versions unspecified

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

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/HT210919 (Release Notes, Vendor Advisory)
support.apple.com/HT210918 (Release Notes, Vendor Advisory)
support.apple.com/HT210921 (Release Notes, Vendor Advisory)
support.apple.com/HT210920 (Release Notes, Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2020-3837?: CVE-2020-3837 is a high-severity vulnerability in Apple iOS, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2020-02-27.
How severe is CVE-2020-3837?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2020-3837 known to be exploited?: Yes. CVE-2020-3837 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-06-27), indicating it is being actively exploited. 5 public proof-of-concept repositories are indexed.