Preface: For our customers’ protection, Apple doesn’t disclose, discuss, or confirm security issues until an investigation has occurred and patches or releases are available.

Background: The assert macro performs a runtime check of the given condition. For example: When a buffer maximum is 8, where the value of i is less that 8 the assert passes. But once i becomes 8 the assert fails causing the program to abort.

Vulnerability details: An expert discovered that even if the screen color is reversed, this vulnerability can be triggered. A memory corruption issue was addressed with improved memory handling.

Impact: An application may be able to execute arbitrary code with kernel privileges.

Official announcement: https://support.apple.com/en-us/HT212846