CVE-2025-43243 is a critical security vulnerability identified in Apple macOS operating systems, stemming from a permissions misconfiguration that allows an unprivileged application to modify protected parts of the file system. This vulnerability is classified under CWE-732, which relates to incorrect permission assignment or management. The issue was addressed by Apple through additional restrictions in macOS Sequoia 15.6, Ventura 13.7.7, and Sonoma 14.7.7. The vulnerability enables an attacker to bypass normal security controls, potentially leading to unauthorized modification of system files, which can compromise system integrity, confidentiality, and availability. The CVSS v3.1 base score of 9.8 reflects its critical nature, with attack vector being network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and full impact on confidentiality, integrity, and availability (C:H/I:H/A:H). This means an attacker can remotely exploit this vulnerability without any authentication or user action, making it highly exploitable. While no known exploits have been reported in the wild yet, the potential impact is severe, including the possibility of persistent malware installation, system takeover, or data destruction. The vulnerability affects unspecified macOS versions prior to the patched releases, so organizations running older versions are at risk. The root cause is a permissions issue that allowed apps to gain unauthorized write access to protected file system areas, which should normally be restricted by the operating system's security model. The fix involves tightening these restrictions to prevent unauthorized modifications.

For European organizations, this vulnerability poses a significant threat due to the widespread use of macOS in enterprise environments, especially in sectors like finance, technology, government, and critical infrastructure. Successful exploitation could lead to complete system compromise, data breaches, ransomware deployment, or disruption of critical services. The ability to modify protected file system areas without authentication or user interaction means attackers can stealthily implant persistent malware or backdoors, evade detection, and maintain long-term access. This could result in intellectual property theft, loss of sensitive customer or employee data, operational downtime, and reputational damage. Given the criticality and ease of exploitation, unpatched macOS systems represent a high-value target for cybercriminals and nation-state actors alike. The impact is exacerbated in environments where macOS devices have elevated privileges or access to sensitive networks. Additionally, the lack of known exploits in the wild currently provides a window for proactive defense, but this may change rapidly once exploit code becomes publicly available.

European organizations should immediately prioritize patching affected macOS systems by deploying the updates macOS Sequoia 15.6, Ventura 13.7.7, or Sonoma 14.7.7 as applicable. Beyond patching, organizations should implement strict application control policies to limit installation of untrusted or unsigned applications, reducing the risk of malicious apps exploiting this vulnerability. Employ endpoint detection and response (EDR) solutions capable of monitoring unauthorized file system modifications and suspicious behaviors indicative of exploitation attempts. Network segmentation should be used to limit the exposure of macOS devices to untrusted networks. Regularly audit and harden file system permissions and review security configurations to ensure no legacy misconfigurations remain. User education should emphasize the risks of installing unverified software. Additionally, organizations should monitor threat intelligence feeds for emerging exploit indicators related to CVE-2025-43243 and be prepared to respond rapidly to any active exploitation attempts. Incident response plans should be updated to include this vulnerability scenario. Finally, consider deploying macOS security features such as System Integrity Protection (SIP) and Full Disk Encryption to add layers of defense.