CVE-2023-42876 is a vulnerability identified in Apple macOS that stems from insufficient bounds checking during the processing of certain files. This flaw can be exploited by an attacker who convinces a user to open or process a specially crafted file, leading to either a denial-of-service (DoS) condition or the potential disclosure of sensitive memory contents. The vulnerability does not require elevated privileges but does require user interaction, such as opening a malicious file. The CVSS v3.1 base score is 7.1, reflecting high severity due to the potential confidentiality impact (disclosure of memory contents) and availability impact (DoS). The vulnerability affects unspecified versions of macOS prior to Sonoma 14, where Apple has implemented improved bounds checks to fix the issue. No known exploits are currently active in the wild, but the flaw represents a significant risk if weaponized. The attack vector is local (AV:L), meaning the attacker must have local access, but no privileges are required (PR:N). The vulnerability scope is unchanged (S:U), indicating it affects only the vulnerable component without impacting other system components. The flaw could be leveraged to extract sensitive information from memory, which may include user data or system secrets, or to crash the system or application, causing denial of service.

For European organizations, the impact of CVE-2023-42876 can be significant, especially in environments where macOS devices are widely used. The potential for denial-of-service can disrupt business operations, particularly in sectors relying on macOS for critical workflows such as creative industries, software development, and education. The possibility of memory disclosure raises confidentiality concerns, potentially exposing sensitive corporate or personal data. This could lead to compliance issues under GDPR if personal data is leaked. Since exploitation requires user interaction, phishing or social engineering could be used to deliver malicious files, increasing the risk in organizations with less mature security awareness. The lack of known active exploits provides a window for proactive mitigation, but the risk remains for targeted attacks. Organizations with mixed OS environments must ensure macOS endpoints are included in vulnerability management and patching processes to prevent lateral movement or data leakage.

To mitigate CVE-2023-42876, European organizations should immediately prioritize updating all macOS devices to Sonoma 14 or later, where the vulnerability is patched with improved bounds checks. Implement strict policies to restrict file sources, especially from untrusted or external origins, to reduce the risk of malicious file processing. Enhance user awareness training to recognize and avoid opening suspicious files, particularly those received via email or messaging platforms. Employ endpoint protection solutions capable of detecting anomalous file processing behavior or crashes indicative of exploitation attempts. Regularly audit and monitor macOS systems for unusual activity or crashes that could signal exploitation attempts. Consider application whitelisting or sandboxing for applications that process files from external sources to limit potential damage. Maintain a robust backup and recovery plan to minimize downtime in case of denial-of-service incidents. Finally, integrate macOS vulnerability management into the broader organizational cybersecurity framework to ensure timely patch deployment and risk assessment.