CVE-2024-27858 is a permissions-related vulnerability in Apple macOS identified as CWE-281 (Improper Restriction of Operations within the Bounds of a Memory Buffer or Improper Access Control). The issue arises from insufficient restrictions on app permissions, allowing an application with low privileges (local access and low complexity) to access protected user data without requiring user interaction. This vulnerability affects macOS versions prior to Sequoia 15, where Apple has introduced additional restrictions to mitigate the problem. The CVSS v3.1 base score is 5.5 (medium), with vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, indicating that the attack requires local access with low privileges, no user interaction, and results in high confidentiality impact but no integrity or availability impact. No public exploits are currently known, and no specific affected versions are detailed beyond the fix in macOS Sequoia 15. The vulnerability could allow unauthorized apps to read sensitive user data, potentially including personal files, credentials, or other protected information, thereby compromising user privacy and confidentiality. The flaw underscores the importance of strict access control enforcement in operating system design, especially for user data protection.

For European organizations, this vulnerability poses a risk primarily to confidentiality of sensitive user data on macOS devices. Sectors such as finance, healthcare, legal, and government agencies that rely on macOS endpoints for handling confidential information are at higher risk. An attacker with local access to a device (e.g., via compromised credentials, insider threat, or physical access) could exploit this flaw to extract protected data without alerting the user. While it does not affect system integrity or availability, the breach of confidentiality could lead to data leaks, regulatory non-compliance (e.g., GDPR violations), reputational damage, and potential financial losses. Organizations with remote or hybrid workforces using macOS laptops may face increased exposure if endpoint security controls are insufficient. The lack of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

The primary mitigation is to upgrade all macOS devices to macOS Sequoia 15 or later, where the vulnerability is fixed by applying additional permission restrictions. Organizations should enforce strict endpoint management policies to ensure timely patch deployment. Additionally, review and restrict app installation policies to limit untrusted or unnecessary applications that could exploit this flaw. Implement strong local access controls, including multi-factor authentication and least privilege principles, to reduce the risk of unauthorized local access. Employ endpoint detection and response (EDR) solutions capable of monitoring suspicious local activity and data access patterns. Conduct regular audits of user permissions and app behaviors on macOS devices. Educate users about physical security and the risks of local device compromise. Finally, maintain up-to-date backups and incident response plans to quickly address any potential data breaches.