CVE-2024-27861 is a vulnerability identified in Apple macOS that allows an application to read restricted memory areas due to improper memory handling, classified under CWE-125 (Out-of-bounds Read). This flaw enables a local attacker to potentially access sensitive information that should be protected by the operating system's memory isolation mechanisms. The vulnerability requires the attacker to have local access to the system and to trick the user into interacting with a malicious application, as indicated by the CVSS vector (AV:L/AC:L/PR:N/UI:R). No privileges are required, which means any user on the system could exploit this if they can run a malicious app and get user interaction. The impact is limited to confidentiality (C:H), with no effect on integrity or availability. The issue was addressed by Apple through improved memory handling in macOS Sequoia 15, which corrects the memory access controls to prevent unauthorized reads. There are no known exploits in the wild at the time of publication, and the affected versions are unspecified but presumably all versions prior to Sequoia 15. This vulnerability could be leveraged to leak sensitive data from memory, potentially exposing credentials, cryptographic keys, or other private information stored in memory segments that should be inaccessible to user applications.

For European organizations, this vulnerability poses a risk of sensitive data leakage on macOS endpoints, which could include corporate laptops, desktops, and servers running macOS. The confidentiality breach could lead to exposure of intellectual property, user credentials, or other sensitive information, potentially facilitating further attacks such as privilege escalation or lateral movement. Although the vulnerability does not affect integrity or availability, the data exposure risk is significant in environments handling sensitive or regulated data, such as financial institutions, healthcare providers, and government agencies. The requirement for local access and user interaction limits remote exploitation but insider threats or social engineering attacks could still leverage this vulnerability. Organizations with a high density of macOS users or those relying on macOS for critical operations are at increased risk. The absence of known exploits reduces immediate threat but does not eliminate the risk of future exploitation once the vulnerability becomes publicly known.

European organizations should prioritize updating all macOS devices to macOS Sequoia 15 or later to apply the fix for CVE-2024-27861. Until updates are deployed, organizations should restrict the installation and execution of untrusted or unsigned applications using macOS Gatekeeper and application whitelisting policies. Employ endpoint protection solutions capable of detecting suspicious local application behavior. Educate users about the risks of running untrusted applications and the importance of avoiding social engineering attempts that could lead to user interaction with malicious apps. Implement strict access controls to limit local user accounts and reduce the attack surface. Regularly audit macOS systems for unauthorized software and monitor logs for unusual activity. For highly sensitive environments, consider additional memory protection mechanisms or sandboxing to isolate applications further. Maintain an inventory of macOS devices to ensure timely patch management and compliance.