CVE-2021-30787

Vulnerability

A memory corruption vulnerability exists in the macOS kernel, specifically in the AMD Kernel component, affecting macOS Big Sur prior to 11.5, macOS Catalina prior to Security Update 2021-004, and macOS Mojave prior to Security Update 2021-005 [1][2][3]. The issue was addressed with improved input validation [1][2][3]. An application may be able to trigger this corruption, leading to unexpected system termination or the ability to write to kernel memory [1].

Exploitation

An attacker would need to have the ability to run a malicious application on the affected system [1]. No additional privileges or user interaction beyond launching the application are required from the description. The application can exploit the memory corruption to escalate its privileges [1][2][3].

Impact

Successful exploitation allows an application to cause unexpected system termination (denial of service) or write arbitrary data to kernel memory [1]. The impact is described as an application may be able to execute arbitrary code with kernel privileges [1][2][3], though the specific CVE-2021-30787 description notes the potential for system termination or kernel memory write.

Mitigation

Apple released fixes on July 21, 2021: macOS Big Sur 11.5, Security Update 2021-004 for Catalina, and Security Update 2021-005 for Mojave [1][2][3]. Users should install the appropriate update for their operating system version. No workarounds were disclosed for unpatched systems.