CVE-2020-3855

Name: CVE-2020-3855
Creator: NVD / NIST
Published: 2020-10-27T21:15:15.023+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.1/10EPSS 0.67%

Last modified Jun 17, 2026

CVE-2020-3855 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. An access issue was addressed with improved access restrictions. This issue is fixed in macOS Catalina 10.15.3, Security Update 2020-001 Mojave, Security Update 2020-001 High Sierra. EPSS estimates a 0.67% chance of exploitation in the next 30 days.

Description

An access issue was addressed with improved access restrictions. This issue is fixed in macOS Catalina 10.15.3, Security Update 2020-001 Mojave, Security Update 2020-001 High Sierra. A malicious application may be able to overwrite arbitrary files.

Metrics

CVSS 3.1

7.1/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

EPSS Probability

0.67%

47.1th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Apple	Mac Os X	< 10.15.3

References

https://support.apple.com/en-us/HT210919Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT210919Release Notes, Vendor Advisory

Timeline

Published: Oct 27, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-3855?

How severe is CVE-2020-3855?

CVE-2020-3855 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.67% probability of exploitation in the next 30 days.

How do I fix CVE-2020-3855?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-3855?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST