CVE-2021-1793: 
macOS vulnerability analysis and mitigation

CVE-2021-1793 is a security vulnerability that affects multiple Apple operating systems including macOS Big Sur, iOS 14.4, iPadOS 14.4, watchOS 7.3, and tvOS 14.4. The vulnerability was discovered by Xingwei Lin of Ant Security Light-Year Lab and was fixed in updates released in January/February 2021. The issue involves processing maliciously crafted images that could lead to arbitrary code execution (Apple Security, NVD).

The vulnerability exists in the ImageIO component of affected Apple operating systems. It was addressed with improved checks in the system. The vulnerability has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H (NVD).

When exploited, this vulnerability could allow an attacker to execute arbitrary code on the target system through processing of a maliciously crafted image. This could potentially lead to unauthorized access and compromise of user information (Apple Security).

Apple addressed this vulnerability in the following updates: macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, watchOS 7.3, tvOS 14.4, iOS 14.4 and iPadOS 14.4. Users should update their devices to these versions or later to mitigate the vulnerability (Apple Security).