CVE-2024-40816 is a vulnerability identified in Apple macOS that stems from an out-of-bounds read condition caused by insufficient input validation. This flaw is classified under CWE-125, which involves reading memory outside the intended buffer boundaries. The vulnerability allows a local attacker with limited privileges (PR:L) to trigger an unexpected system shutdown, impacting system availability (A:H) without affecting confidentiality or integrity. The attack vector is local, requiring no user interaction (UI:N), and the scope remains unchanged (S:U). Affected macOS versions include Sonoma 14.6, Monterey 12.7.6, and Ventura 13.6.8, where Apple has implemented patches to address the input validation issue. The vulnerability can be exploited by a local attacker who can execute code or commands on the system, potentially causing a denial-of-service by forcing the system to shut down unexpectedly. Although no exploits are currently known in the wild, the medium CVSS score of 5.5 reflects the moderate risk posed by this vulnerability due to its impact on availability and ease of exploitation by local attackers. The vulnerability highlights the importance of robust input validation to prevent memory safety issues that can lead to system instability.

For European organizations, this vulnerability primarily threatens system availability by enabling local attackers to cause unexpected shutdowns of macOS devices. This can disrupt business operations, especially in environments where macOS systems are critical for daily workflows, such as creative industries, software development, and certain administrative functions. The impact is more pronounced in organizations with shared or multi-user systems where local access controls may be weaker. While confidentiality and integrity are not directly affected, repeated or targeted exploitation could lead to denial-of-service conditions, affecting productivity and potentially causing data loss if unsaved work is interrupted. In sectors like finance, healthcare, and government, where operational continuity is crucial, such disruptions could have cascading effects. Additionally, the need for local access limits remote exploitation but raises concerns about insider threats or compromised local accounts. European organizations should consider the risk of this vulnerability in their endpoint security posture and incident response planning.

To mitigate CVE-2024-40816, European organizations should prioritize updating affected macOS systems to the patched versions: Sonoma 14.6, Monterey 12.7.6, and Ventura 13.6.8. Restrict local access to macOS devices by enforcing strict user account controls and limiting administrative privileges to trusted personnel only. Implement endpoint detection and response (EDR) solutions capable of monitoring for unusual local activity that could indicate exploitation attempts. Regularly audit and harden local user permissions to reduce the risk of unauthorized local access. Educate users about the risks of local privilege escalation and the importance of reporting unexpected system behavior. In environments with shared macOS devices, consider additional physical security controls to prevent unauthorized physical access. Maintain comprehensive backups to mitigate the impact of potential denial-of-service caused by unexpected shutdowns. Finally, integrate this vulnerability into vulnerability management workflows to ensure timely patch deployment and verification.