An issue was discovered in certain Apple products. macOS before 10.12.6 is affected. The issue involves the "afclip" component. It allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted audio file.
Apple Security Advisory 2017-07-19-2 - macOS 10.12.6 is now available and addresses code execution, memory corruption, and various other vulnerabilities.