Big Sur 11.3 patches a zero-day vulnerability that could allow an attacker to craft malicious payloads that will not be checked by Gatekeeper, the security check built into Apples operating system that is supposed to block the execution of software from untrusted sources. The vulnerability, dubbed CVE-2021-1810, was found by the boffins at F-Secure in December 2020, and has been used in in-the-wild attacks as far back as January 9 2021.”]

