CVE-2021-30739: 
macOS vulnerability analysis and mitigation

CVE-2021-30739 is a memory corruption vulnerability discovered in Apple's macOS kernel that was disclosed and patched in May 2021. The vulnerability affects multiple versions of macOS including Big Sur, Catalina, and Mojave. It was discovered by Zuozhi Fan of Ant Group Tianqiong Security Lab (Apple Support).

The vulnerability is classified as a memory corruption issue in the kernel that was addressed with improved validation. It has a CVSS v3.1 base score of 7.8 (HIGH) with the vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, indicating local access required with low attack complexity (NVD).

If exploited, this vulnerability allows a local attacker to elevate their privileges on the affected system. The high CVSS score indicates potential severe impacts on system confidentiality, integrity, and availability (NVD).

The vulnerability requires local access to exploit, with low attack complexity and low privileges required. No public exploits were confirmed at the time of disclosure (NVD).

Apple addressed this vulnerability in macOS Big Sur 11.4, Security Update 2021-003 Catalina, and Security Update 2021-004 Mojave. Users are advised to update to these versions to mitigate the vulnerability (Apple Support, Apple Support, Apple Support).