CVE-2016-4717

Vulnerability

The File Bookmark component in Apple OS X before version 10.12 mishandles scoped-bookmark file descriptors. This vulnerability allows a crafted application to trigger a denial of service condition. The issue exists in the handling of file descriptors associated with scoped bookmarks, which are used for persistent access to files outside the app's sandbox. Affected versions include OS X 10.11.x and earlier.

Exploitation

An attacker must provide a specially crafted app to the user and convince them to run it. No special network position or authentication is required; the attack is local. Once executed, the app can exploit the mishandling of scoped-bookmark file descriptors to cause the system to become unresponsive or crash, resulting in a denial of service.

Impact

Successful exploitation results in a denial of service, impacting system availability. There is no indication of information disclosure or privilege escalation. The attacker gains no additional access beyond causing the system to hang or restart.

Mitigation

Apple addressed this issue in macOS Sierra 10.12, released on September 20, 2016 [1]. Users should update to macOS 10.12 or later. No workarounds are documented, and the vulnerability is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog.