CVE-2025-43243 is a critical vulnerability identified in Apple macOS operating systems, including macOS Sequoia 15.6, macOS Ventura 13.7.7, and macOS Sonoma 14.7.7. The vulnerability stems from a permissions issue that allows an application to modify protected parts of the file system without requiring any user interaction or prior authentication. This flaw is categorized under CWE-732, which relates to incorrect permission assignment for critical resources. The vulnerability has a CVSS v3.1 base score of 9.8, indicating a critical severity level. The attack vector is network-based (AV:N), with low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:N). The scope is unchanged (S:U), but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). An attacker exploiting this vulnerability could gain unauthorized write access to sensitive system files, potentially leading to full system compromise, privilege escalation, installation of persistent malware, or disruption of system operations. Although no known exploits are currently reported in the wild, the ease of exploitation and the critical impact make this a significant threat. Apple has addressed this issue by implementing additional restrictions on permissions in the affected macOS versions, emphasizing the importance of applying these updates promptly to mitigate the risk.

For European organizations, this vulnerability poses a substantial risk, especially those relying on Apple macOS systems in their IT infrastructure. The ability for an unprivileged app to modify protected file system areas could lead to unauthorized data access, data corruption, or complete system takeover. This could disrupt business operations, lead to data breaches involving sensitive personal or corporate information, and damage organizational reputation. Sectors such as finance, healthcare, government, and technology, which often use macOS devices, could face regulatory and compliance repercussions under GDPR if personal data is compromised. Additionally, the potential for malware persistence and lateral movement within networks increases the threat landscape. Given the critical nature of the vulnerability and the lack of required user interaction or privileges, attackers could automate exploitation at scale, increasing the risk to European enterprises and public sector entities.

European organizations should prioritize immediate deployment of the security updates released by Apple for macOS Sequoia 15.6, Ventura 13.7.7, and Sonoma 14.7.7. Beyond patching, organizations should implement application whitelisting to restrict execution of unauthorized or untrusted applications. Employ endpoint detection and response (EDR) solutions capable of monitoring and alerting on anomalous file system modifications, especially in protected directories. Enforce strict device management policies using Mobile Device Management (MDM) tools to control app installations and permissions. Regularly audit system permissions and file integrity using automated tools to detect unauthorized changes. Network segmentation can limit the spread of compromise if exploitation occurs. Additionally, educating users about the risks of installing untrusted applications and maintaining robust backup strategies will aid in recovery if an incident arises.