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.
http://packetstormsecurity.com/files/161296/XNU-Kernel-Mach-Message-Trailers-Memory-Disclosure.html
http://seclists.org/fulldisclosure/2020/Dec/32
https://support.apple.com/en-us/HT211928
https://support.apple.com/en-us/HT211929
https://support.apple.com/en-us/HT211931
https://support.apple.com/en-us/HT211940
https://support.apple.com/en-us/HT211944
https://support.apple.com/en-us/HT211945
Source: MITRE
Published: 2020-12-08
Updated: 2021-02-11
Type: CWE-665
Base Score: 7.1
Vector: AV:N/AC:M/Au:N/C:C/I:N/A:N
Impact Score: 6.9
Exploitability Score: 8.6
Severity: HIGH
Base Score: 5.5
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Impact Score: 3.6
Exploitability Score: 1.8
Severity: MEDIUM