CVE-2024-40842 is a vulnerability identified in Apple macOS that stems from improper validation of environment variables by applications. This flaw allows an application running with limited privileges (local access with low privileges) to access sensitive user data that should otherwise be protected. The vulnerability is categorized under CWE-200, indicating an information exposure issue. The root cause is insufficient validation of environment variables, which can be manipulated to expose sensitive information to unauthorized applications. The vulnerability affects macOS versions prior to Sequoia 15, where Apple has implemented improved validation mechanisms to mitigate the issue. The CVSS v3.1 score is 5.5 (medium severity), reflecting that the attack vector is local (AV:L), requires low privileges (PR:L), no user interaction (UI:N), and impacts confidentiality (C:H) without affecting integrity or availability. There are no known exploits in the wild at this time, but the vulnerability presents a risk especially in environments where untrusted or potentially malicious applications can be installed or executed locally. The vulnerability does not require user interaction, which increases the risk if an attacker gains local access. The fix involves improved validation of environment variables to prevent unauthorized data access.

For European organizations, the primary impact of CVE-2024-40842 is the potential unauthorized disclosure of sensitive user data on macOS systems. This could lead to privacy violations, leakage of confidential information, and potential compliance issues with data protection regulations such as GDPR. Since the vulnerability requires local access with low privileges, the risk is elevated in environments where endpoint security is weak or where users can install untrusted applications. The confidentiality breach could affect intellectual property, personal data, and other sensitive information stored or accessible on affected macOS devices. Although the vulnerability does not affect system integrity or availability, the exposure of sensitive data could facilitate further attacks or insider threats. Organizations with macOS-heavy environments, especially in sectors like finance, technology, and government, may face increased risk. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits targeting this vulnerability.

1. Upgrade all macOS systems to macOS Sequoia 15 or later, where the vulnerability is fixed. 2. Implement strict application control policies to prevent installation or execution of untrusted or unauthorized applications on macOS endpoints. 3. Employ endpoint detection and response (EDR) solutions capable of monitoring and restricting suspicious local application behaviors, particularly those attempting to manipulate environment variables. 4. Conduct regular audits of installed applications and environment variable configurations to detect anomalies. 5. Educate users on the risks of installing untrusted software and enforce least privilege principles to limit local access rights. 6. Use mobile device management (MDM) solutions to enforce security policies and ensure timely patch deployment across all macOS devices. 7. Monitor for unusual access patterns to sensitive data that could indicate exploitation attempts. 8. Maintain up-to-date backups and incident response plans to quickly address any data exposure incidents.