A privacy issue existed in motion sensor calibration. This issue was addressed with improved motion sensor processing. This issue is fixed in iOS 12.2, watchOS 5.2. A malicious app may be able to track users between installs.
https://support.apple.com/HT209602
https://support.apple.com/HT209599
Source: Mitre, NVD
Published: 2019-12-18
Updated: 2019-12-30
Base Score: 2.1
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N
Severity: Low
Base Score: 3.3
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N