CVE-2023-42877 is a vulnerability in Apple macOS that allows an application to modify protected parts of the file system. This issue arises due to insufficient validation checks within the operating system, enabling an app to bypass normal file system protections. The vulnerability affects multiple macOS versions prior to the patched releases: Sonoma 14.1, Monterey 12.7.1, and Ventura 13.6.1. The CVSS v3.1 score is 7.7 (high), with an attack vector classified as local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality and integrity (C:H/I:H), but no impact on availability (A:N). This means an attacker with local access can exploit the vulnerability without authentication or user interaction to gain unauthorized write access to critical system files, potentially leading to system compromise or persistent malware installation. Apple addressed the issue by implementing improved checks to prevent unauthorized modifications. No public exploits have been reported yet, but the vulnerability's nature makes it a significant risk if exploited. The vulnerability is particularly concerning because it allows modification of protected file system areas, which could undermine system security controls and lead to further attacks.

For European organizations, the impact of CVE-2023-42877 can be substantial. Unauthorized modification of protected system files can lead to system integrity breaches, enabling attackers to install persistent malware, escalate privileges, or disrupt security mechanisms. Confidential data could be exposed or altered, affecting compliance with data protection regulations such as GDPR. The vulnerability requires local access but no privileges or user interaction, increasing the risk from insider threats or attackers who gain initial footholds through other means. Organizations relying on macOS for critical operations, development, or sensitive data processing may face operational disruptions and reputational damage if exploited. The absence of known exploits in the wild currently reduces immediate risk, but the high severity and ease of exploitation warrant urgent patching and monitoring.

1. Immediately update all macOS systems to the patched versions: Sonoma 14.1, Monterey 12.7.1, or Ventura 13.6.1, depending on the installed version. 2. Restrict installation of applications to trusted sources, such as the Apple App Store or verified developers, to reduce the risk of malicious apps exploiting this vulnerability. 3. Implement strict endpoint security controls, including application whitelisting and behavior monitoring, to detect unauthorized file system modifications. 4. Limit local access to macOS systems by enforcing strong physical security and user access controls, minimizing the risk of local exploitation. 5. Regularly audit system integrity using tools that can detect unauthorized changes to protected file system areas. 6. Educate users about the risks of installing untrusted software and the importance of applying security updates promptly. 7. Monitor security advisories and threat intelligence feeds for any emerging exploits targeting this vulnerability.