CVE-2023-42887 is a sandbox escape vulnerability in Apple macOS that allows a local application to read arbitrary files on the system. The root cause is an access control issue where sandbox restrictions were insufficiently enforced, enabling an app to bypass intended file access limitations. This vulnerability affects macOS versions prior to Ventura 13.6.4 and Sonoma 14.2, where the sandbox environment failed to fully isolate app file system access. Exploitation requires the attacker to have local access to the system and to trick the user into interacting with the malicious app, as user interaction is necessary. The vulnerability does not require prior authentication, meaning any app running on the user's account could potentially exploit it. The impact is primarily on confidentiality, as unauthorized reading of arbitrary files could expose sensitive user or system data. Integrity and availability are not impacted by this flaw. Apple has fixed the issue by implementing additional sandbox restrictions in the updated macOS versions. No public exploits or active exploitation campaigns have been reported to date, but the medium CVSS score of 6.3 reflects the moderate risk due to local access and user interaction requirements. This vulnerability highlights the importance of sandbox enforcement in protecting user data on macOS systems.

For European organizations, this vulnerability poses a risk of unauthorized data disclosure if attackers can convince users to run malicious applications locally. Sensitive files, including corporate documents, credentials, or configuration files, could be exposed, leading to potential data breaches or intellectual property theft. Organizations with employees using macOS devices, especially in sectors like finance, healthcare, and government, may face increased risk due to the potential sensitivity of exposed data. Although exploitation requires local access and user interaction, phishing or social engineering attacks could facilitate this. The vulnerability does not affect system integrity or availability, so it is less likely to cause operational disruption but remains a significant confidentiality concern. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time. Organizations relying on macOS for endpoint computing should prioritize patching to mitigate this exposure.

European organizations should implement the following specific mitigations: 1) Deploy macOS updates promptly, specifically upgrading to Ventura 13.6.4 or Sonoma 14.2 or later, to apply the sandbox restriction fixes. 2) Enforce strict application control policies to limit installation and execution of untrusted or unsigned applications, reducing the risk of malicious apps exploiting this vulnerability. 3) Educate users on the risks of running unknown or unverified applications and the importance of avoiding suspicious downloads or email attachments to prevent social engineering vectors. 4) Utilize endpoint detection and response (EDR) solutions capable of monitoring for unusual file access patterns or sandbox escape attempts on macOS devices. 5) Implement least privilege principles for user accounts to minimize the impact of local exploits. 6) Regularly audit and monitor macOS systems for unauthorized software installations or anomalous behavior. These targeted steps go beyond generic patching advice by focusing on user behavior, application control, and monitoring to reduce exploitation likelihood.