CVE-2024-40847 is a vulnerability identified in Apple macOS that permits an application to access sensitive user data due to insufficient code-signing restrictions. The vulnerability affects multiple recent macOS versions prior to Ventura 13.7, Sonoma 14.7, and Sequoia 15, where the issue has been fixed. The core technical problem lies in the ability of an app with limited privileges (local access and low complexity) to bypass certain code-signing enforcement mechanisms, thereby gaining unauthorized read access to sensitive user data. The vulnerability does not require user interaction, which increases its risk profile, but it does require local access and some privileges, limiting remote exploitation. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N) indicates that the attack vector is local, with low attack complexity, requiring low privileges, no user interaction, unchanged scope, and high confidentiality impact without affecting integrity or availability. No known exploits have been reported in the wild as of the publication date. Apple addressed this issue by implementing additional code-signing restrictions to prevent unauthorized data access by applications. This vulnerability is particularly relevant for environments where sensitive user data is stored on macOS devices and where local access controls may be insufficient or compromised.

For European organizations, the primary impact of CVE-2024-40847 is the potential unauthorized disclosure of sensitive user data on macOS devices. This could lead to privacy breaches, intellectual property theft, or exposure of confidential business information. Sectors such as finance, healthcare, government, and technology, which often handle sensitive personal or corporate data, are at higher risk. The requirement for local access and low privileges means that insider threats or attackers who have gained limited footholds on devices could exploit this vulnerability to escalate data access without detection. Although the vulnerability does not affect system integrity or availability, the confidentiality breach alone can have regulatory and reputational consequences, especially under GDPR and other European data protection laws. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits over time. Organizations relying heavily on macOS endpoints must consider this vulnerability in their risk assessments and incident response planning.

Organizations should immediately apply the security updates provided by Apple in macOS Ventura 13.7, Sonoma 14.7, and Sequoia 15 to remediate this vulnerability. Beyond patching, implement strict application whitelisting policies to restrict execution of unauthorized or untrusted applications, reducing the risk of local exploitation. Employ endpoint detection and response (EDR) tools capable of monitoring unusual file access patterns or privilege escalations on macOS devices. Enforce least privilege principles to limit user and application permissions, minimizing the potential impact of compromised accounts. Regularly audit local user accounts and installed applications to detect and remove unnecessary or potentially malicious software. Educate users about the risks of installing untrusted applications and the importance of reporting suspicious activity. For high-security environments, consider additional controls such as disk encryption, multi-factor authentication for local logins, and network segmentation to limit lateral movement after local compromise.