CVE-2024-40811 is a vulnerability in Apple macOS that allows an application to modify protected parts of the file system. The vulnerability arises from insufficient security checks that previously allowed unauthorized modification of critical system files or directories. This flaw is categorized under CWE-281, which relates to improper access control. The vulnerability affects unspecified versions of macOS prior to the release of macOS Sonoma 14.6, where Apple implemented enhanced validation mechanisms to prevent unauthorized file system modifications. The CVSS v3.1 base score is 8.4, reflecting high severity due to the vulnerability's impact on confidentiality, integrity, and availability (all rated high). The attack vector is local (AV:L), requiring the attacker to have local access but no privileges (PR:N) or user interaction (UI:N). This means any malicious app running on the system can exploit the vulnerability without needing elevated permissions or user consent. The scope is unchanged (S:U), indicating the vulnerability affects resources managed by the same security authority. Although no known exploits have been reported in the wild, the vulnerability poses a significant risk since it enables unauthorized modification of protected system files, potentially allowing attackers to implant persistent malware, escalate privileges, or disrupt system operations. The vulnerability's fix involves improved access control checks to ensure only authorized processes can modify protected file system areas.

For European organizations, this vulnerability presents a serious threat, especially those relying on macOS devices for sensitive operations, including government agencies, financial institutions, and critical infrastructure providers. Unauthorized modification of protected file system areas can lead to persistent malware infections, data breaches, and system instability. The ability to alter system files without authentication or user interaction increases the risk of stealthy attacks that can evade detection and persist through reboots. This could facilitate espionage, sabotage, or ransomware deployment. Organizations with remote or hybrid workforces using macOS devices are particularly vulnerable, as local access could be gained through compromised endpoints or insider threats. The impact extends to the integrity of software supply chains and development environments that rely on macOS, potentially undermining trust in software artifacts. Given the high CVSS score and the critical nature of the affected systems, failure to address this vulnerability could result in significant operational and reputational damage.

1. Immediately update all macOS devices to version Sonoma 14.6 or later, where the vulnerability is patched. 2. Implement strict application whitelisting policies to prevent unauthorized or untrusted applications from executing on macOS endpoints. 3. Deploy endpoint detection and response (EDR) solutions capable of monitoring and alerting on unauthorized file system modifications, particularly in protected directories. 4. Enforce least privilege principles by restricting user permissions and avoiding running applications with unnecessary elevated privileges. 5. Conduct regular audits of system file integrity using tools such as Apple’s System Integrity Protection (SIP) and third-party integrity checkers. 6. Educate users and administrators about the risks of installing unverified software and the importance of timely patching. 7. For organizations with macOS device management, use Mobile Device Management (MDM) solutions to enforce patch compliance and security policies. 8. Monitor internal threat intelligence sources for any emerging exploit attempts targeting this vulnerability. 9. Consider network segmentation to limit the impact of compromised macOS devices within the enterprise environment. 10. Develop and test incident response plans specific to macOS endpoint compromises.