CVE 2019-6224
A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 12.1.3, macOS Mojave 10.14.3, tvOS 12.1.2, watchOS 5.1.3. A remote attacker may be able to initiate a FaceTime call causing arbitrary code execution.
See the 
CVE page on Mitre.org
for more details.
