CVE-2024-40864 is a vulnerability in Apple macOS related to improper handling of certain network protocols, which allows an attacker positioned with privileged network access to track user activity. The vulnerability is categorized under CWE-200, indicating an information disclosure issue. Specifically, an attacker who can observe or manipulate network traffic—such as someone on the same Wi-Fi network or controlling a network router—can infer or monitor user activity patterns without needing to compromise the endpoint directly or require user interaction. The vulnerability does not allow modification or disruption of data (no integrity or availability impact) but leaks limited confidential information about user behavior. Apple addressed this issue in macOS Ventura 13.7.5 and macOS Sonoma 14.7.5 by improving protocol handling to prevent such tracking. The CVSS v3.1 base score is 2.7 (low severity), reflecting the requirement for privileged network position and the limited impact scope. No public exploits have been reported, indicating low current exploitation risk. However, the vulnerability is relevant in environments where network attackers may be present, such as public or poorly secured networks. Organizations relying on macOS devices should ensure timely patching to mitigate this risk.

For European organizations, the primary impact of CVE-2024-40864 is a confidentiality breach through user activity tracking by attackers with privileged network access. This could lead to privacy violations, targeted surveillance, or profiling of users, which is particularly sensitive under stringent European data protection regulations like GDPR. While the vulnerability does not allow data modification or service disruption, the ability to monitor user activity could aid further targeted attacks or espionage, especially in sectors handling sensitive information such as finance, government, healthcare, and critical infrastructure. Organizations with macOS endpoints operating in environments with untrusted or shared networks (e.g., remote work, public Wi-Fi) are at higher risk. The limited severity and lack of known exploits reduce immediate threat levels, but the potential for privacy compromise necessitates proactive patching and network security controls.

1. Immediately update all macOS devices to Ventura 13.7.5, Sonoma 14.7.5, or later versions containing the patch to eliminate the vulnerability. 2. Restrict privileged network positions by segmenting networks, using VLANs, and enforcing strict access controls to limit exposure to potential attackers. 3. Employ network monitoring and anomaly detection tools to identify unusual traffic patterns indicative of activity tracking attempts. 4. Use encrypted communication protocols (e.g., VPNs, TLS) to reduce the risk of traffic interception and analysis. 5. Educate users about the risks of connecting to untrusted or public networks and encourage use of secure connections. 6. Implement endpoint security solutions that can detect suspicious network behavior or unauthorized access attempts. 7. Regularly audit network infrastructure to ensure no unauthorized devices have privileged network access.