CVE-2020-27950

Name: CVE-2020-27950
Creator: NVD / NIST
Published: 2020-12-08T21:15:13.967+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10Actively ExploitedEPSS 16.52%

Last modified Jun 17, 2026

CVE-2020-27950 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. A memory initialization issue was addressed. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 12.4.9, watchOS 6.2.9, Security Update 2020-006 High Sierra, Security Update 2020-006 Mojave, iOS 14.2 and iPadOS 14.2, watchOS 5.3.9, macOS Catalina 10.15.7 Supplemental Update, macOS Catalina 10.15.7 Update. CISA has confirmed active exploitation in the wild. EPSS estimates a 16.52% chance of exploitation in the next 30 days.

Description

A memory initialization issue was addressed. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 12.4.9, watchOS 6.2.9, Security Update 2020-006 High Sierra, Security Update 2020-006 Mojave, iOS 14.2 and iPadOS 14.2, watchOS 5.3.9, macOS Catalina 10.15.7 Supplemental Update, macOS Catalina 10.15.7 Update. A malicious application may be able to disclose kernel memory.

Metrics

CVSS 3.1

5.5/10

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

EPSS Probability

16.52%

96.6th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by May 3, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apple	Ipados	< 14.2
Apple	Iphone Os	< 12.4.9
Apple	Iphone Os	>= 14.0, < 14.2
Apple	Macos	< 10.15.7
Apple	Macos	>= 11.0, < 11.0.1
Apple	Watchos	< 5.3.9
Apple	Watchos	>= 6.0, < 6.2.9
Apple	Watchos	>= 7.0, < 7.1

References

http://packetstormsecurity.com/files/161296/XNU-Kernel-Mach-Message-Trailers-Memory-Disclosure.htmlThird Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2020/Dec/32Mailing List, Third Party Advisory
https://support.apple.com/en-us/HT211928Vendor Advisory
https://support.apple.com/en-us/HT211929Vendor Advisory
https://support.apple.com/en-us/HT211931Vendor Advisory
https://support.apple.com/en-us/HT211940Vendor Advisory
https://support.apple.com/en-us/HT211944Vendor Advisory
https://support.apple.com/en-us/HT211945Vendor Advisory
https://support.apple.com/en-us/HT211946Vendor Advisory
https://support.apple.com/en-us/HT211947Vendor Advisory
http://packetstormsecurity.com/files/161296/XNU-Kernel-Mach-Message-Trailers-Memory-Disclosure.htmlThird Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2020/Dec/32Mailing List, Third Party Advisory
https://support.apple.com/en-us/HT211928Vendor Advisory
https://support.apple.com/en-us/HT211929Vendor Advisory
https://support.apple.com/en-us/HT211931Vendor Advisory
https://support.apple.com/en-us/HT211940Vendor Advisory
https://support.apple.com/en-us/HT211944Vendor Advisory
https://support.apple.com/en-us/HT211945Vendor Advisory
https://support.apple.com/en-us/HT211946Vendor Advisory
https://support.apple.com/en-us/HT211947Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-27950US Government Resource

Timeline

Published: Dec 8, 2020
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2020-27950?

How severe is CVE-2020-27950?

CVE-2020-27950 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 16.52% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2020-27950?

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-2020-27950?

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

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Source: NVD / NIST