CVE-2024-40855 is a vulnerability identified in Apple macOS that allows a sandboxed application to access sensitive user data due to insufficient enforcement of access control policies. Sandboxing is a security mechanism designed to isolate applications and restrict their access to system resources and user data. However, this vulnerability stems from a flaw in the sandbox implementation or policy checks that permits an app running with limited privileges to bypass these restrictions and read sensitive information it should not have access to. The vulnerability affects multiple macOS versions prior to the patched releases: Ventura 13.7.1, Sequoia 15, and Sonoma 14.7.1. The CVSS 3.1 base score is 5.5 (medium severity), with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), requiring low privileges (PR:L), no user interaction (UI:N), unchanged scope (S:U), high confidentiality impact (C:H), and no impact on integrity or availability (I:N/A:N). This means an attacker with local access and low privileges can exploit the vulnerability without user interaction to gain unauthorized access to sensitive data, compromising confidentiality. The issue was addressed by Apple through improved access checks in the sandbox enforcement mechanism. No public exploits or active exploitation have been reported to date. The vulnerability is categorized under CWE-863 (Incorrect Authorization).

For European organizations, the primary impact of CVE-2024-40855 is the potential unauthorized disclosure of sensitive user data on macOS systems. This could include personal information, credentials, or corporate data accessible to sandboxed applications. Since the vulnerability requires local access with low privileges, it poses a risk mainly from insider threats, compromised user accounts, or malicious software installed on endpoints. The confidentiality breach could lead to data leaks, regulatory non-compliance (e.g., GDPR violations), reputational damage, and potential financial losses. Organizations relying heavily on macOS devices, such as creative industries, software development firms, and certain government agencies, may be more vulnerable. The lack of impact on integrity and availability limits the threat to data exposure rather than system disruption. However, the ease of exploitation without user interaction increases the risk profile, especially in environments where endpoint security controls are weak or where users have elevated privileges.

1. Immediately apply the security updates released by Apple: macOS Ventura 13.7.1, macOS Sequoia 15, and macOS Sonoma 14.7.1 or later versions. 2. Restrict the installation of applications to trusted sources such as the Apple App Store or enterprise-approved software repositories to reduce the risk of malicious sandboxed apps. 3. Implement strict endpoint security policies including application whitelisting and monitoring for anomalous app behavior that could indicate exploitation attempts. 4. Enforce the principle of least privilege for user accounts to minimize the potential for local privilege exploitation. 5. Conduct regular audits of installed applications and sandbox permissions to detect unauthorized or suspicious apps. 6. Educate users about the risks of installing untrusted software and the importance of applying system updates promptly. 7. Utilize macOS security features such as System Integrity Protection (SIP) and Endpoint Detection and Response (EDR) tools to enhance detection and prevention capabilities.