CVE-2021-1759: 
macOS vulnerability analysis and mitigation

CVE-2021-1759 is a security vulnerability discovered in Apple's CoreMedia component that was disclosed and patched in February 2021. The vulnerability was identified by Hou JingYi (@hjy79425575) of Qihoo 360 CERT. It affects multiple Apple operating systems including macOS Big Sur 11.2, iOS 14.4, iPadOS 14.4, and tvOS 14.4 (Apple Support, Apple iOS).

The vulnerability is characterized as an out-of-bounds read issue in the CoreMedia component that was addressed with improved input validation. The vulnerability has a CVSS v3.1 Base Score of 7.8 (HIGH) with the vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H (NVD).

When exploited, processing a maliciously crafted image may lead to arbitrary code execution on the affected system. This could potentially allow attackers to execute unauthorized code and compromise the security of the affected device (Apple Support).

Apple addressed this vulnerability by implementing improved input validation in the CoreMedia component. The fix was released in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, iOS 14.4 and iPadOS 14.4. Users are advised to update their devices to these versions or later to protect against this vulnerability (Apple Support).