CVE-2023-42858 is a vulnerability identified in Apple macOS that allows an application with limited privileges to access user-sensitive data due to insufficient access control checks. The vulnerability does not require user interaction but does require that the attacker has local privileges on the system, which could be through a less-privileged app or process. The flaw affects multiple macOS versions prior to the patched releases: macOS Sonoma 14.1, Monterey 12.7.1, and Ventura 13.6.1. The core issue stems from improper validation of access permissions, enabling an app to bypass intended restrictions and read sensitive user data, potentially including personal files or information stored by other applications. The vulnerability does not impact system integrity or availability, meaning it cannot be used to modify data or crash the system, but it compromises confidentiality. Apple addressed the issue by implementing improved access checks in the patched versions. The CVSS v3.1 score of 5.5 reflects a medium severity, considering the local attack vector, low complexity, required privileges, and no user interaction. There are no known exploits in the wild at this time, but the potential for data leakage makes it a concern for organizations handling sensitive information. The vulnerability highlights the importance of strict access control enforcement in operating systems to prevent unauthorized data exposure.

For European organizations, this vulnerability primarily threatens the confidentiality of sensitive user data on macOS devices. Organizations in sectors such as finance, healthcare, legal, and government, which often handle confidential personal or corporate data, could be at risk if attackers gain local access to macOS systems. The ability for a low-privileged app to access sensitive data could lead to data breaches, intellectual property theft, or exposure of personal identifiable information (PII), potentially resulting in regulatory penalties under GDPR. Although the vulnerability does not affect system integrity or availability, the confidentiality breach alone can cause reputational damage and financial loss. The risk is heightened in environments where macOS devices are used extensively and where endpoint security controls are insufficient to prevent installation or execution of untrusted applications. Since exploitation requires local privileges, the threat is more relevant in scenarios involving insider threats, compromised user accounts, or malware that has already gained some foothold on the system.

European organizations should prioritize updating all affected macOS devices to the patched versions: Sonoma 14.1, Monterey 12.7.1, or Ventura 13.6.1. Beyond patching, organizations should enforce strict application control policies to prevent installation of untrusted or unauthorized apps, reducing the risk of local exploitation. Employ endpoint protection solutions capable of detecting suspicious local activity or privilege escalation attempts. Implement least privilege principles for user accounts to limit the ability of apps to gain elevated access. Regularly audit installed applications and running processes on macOS endpoints to identify and remove potentially malicious or unnecessary software. Educate users about the risks of installing untrusted applications and the importance of reporting suspicious behavior. For highly sensitive environments, consider using macOS security features such as System Integrity Protection (SIP) and Full Disk Encryption (FileVault) to add layers of defense. Finally, monitor security advisories from Apple and update systems promptly to mitigate emerging threats.