CVE-2021-1753: 
macOS vulnerability analysis and mitigation

CVE-2021-1753 is an out-of-bounds read vulnerability discovered in Apple's Model I/O component. The vulnerability was disclosed on April 2, 2021, and affects multiple Apple operating systems including macOS Big Sur, Catalina, Mojave, iOS 14.4, and iPadOS 14.4. The issue was discovered by Mickey Jin of Trend Micro working with Trend Micro's Zero Day Initiative (Apple Advisory, NVD).

The vulnerability is classified as an out-of-bounds read issue (CWE-125) in the Model I/O component. It has a CVSS v3.1 base score of 7.8 (HIGH) with vector CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. The vulnerability requires local access and user interaction but no privileges, while potentially impacting confidentiality, integrity, and availability at a high level (NVD).

When exploited, processing a maliciously crafted image may lead to arbitrary code execution on the affected system. This could allow attackers to execute malicious code with the privileges of the Model I/O process (Apple Advisory).

Apple has addressed this vulnerability by improving bounds checking in the following security updates: macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. Users are advised to update to these versions or later to mitigate the vulnerability (Apple Advisory).