A user privacy issue was addressed by removing the broadcast MAC address. This issue is fixed in iOS 12.3, tvOS 12.3, watchOS 5.2.1. A device may be passively tracked by its WiFi MAC address.
https://support.apple.com/HT210122
https://support.apple.com/HT210120
https://support.apple.com/HT210118
Source: Mitre, NVD
Published: 2019-12-18
Updated: 2019-12-20
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity: High