CVE-2021-1769: 
macOS vulnerability analysis and mitigation

CVE-2021-1769 is a security vulnerability discovered in Apple's Swift programming language that affects multiple Apple operating systems including macOS Big Sur 11.2, iOS 14.4, iPadOS 14.4, watchOS 7.3, and tvOS 14.4. The vulnerability was disclosed and patched in January 2021. It involves a logic issue that could allow a malicious attacker with arbitrary read and write capability to bypass Pointer Authentication (Apple Security).

The vulnerability stems from a logic issue in Swift's implementation of Pointer Authentication. The security flaw was addressed by Apple through improved validation mechanisms. The vulnerability has a CVSS v3.1 base score of 5.5 (Medium) with a vector string of CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N, indicating local access is required and the impact primarily affects integrity (NVD).

If exploited, this vulnerability could allow an attacker with arbitrary read and write capabilities to bypass Pointer Authentication, a security feature designed to prevent memory corruption attacks. This could potentially lead to unauthorized code execution or privilege escalation on affected systems (Apple Security).

Apple addressed this vulnerability in the following system 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 are advised to update their systems to these versions or later to protect against this vulnerability (Apple Security).