Google Project Zero researchers detailed a new high-severity macOS flaw after Apple failed to patch it by the 90-day disclosure deadline. The flaw exists in a process called copy-on-write (COW) in Apples XNU kernel. COW allows copies of data between processes to be created for anonymous memory and file mappings. The vulnerability was first reported Nov. 30 by Google Zero researcher Ian Beer. Apple did not immediately respond to a request for comment from Threatpost.”]