CVE-2023-40430 is a logic vulnerability in Apple macOS that permits an application to bypass user consent mechanisms and access removable volumes. The root cause is an insufficient validation of access permissions when apps attempt to interact with external storage devices, such as USB drives or external hard disks. This flaw allows an app, potentially with limited privileges and requiring user interaction, to read data from removable media without the user's explicit approval, violating the intended security model designed to protect user privacy and data confidentiality. The vulnerability was addressed in macOS Sonoma 14 by implementing improved checks that enforce user consent before granting access to removable volumes. The CVSS v3.1 base score is 5.5 (medium severity), reflecting that the attack vector is local (AV:L), requires low attack complexity (AC:L), no privileges (PR:N), but user interaction (UI:R) is necessary. The impact is limited to confidentiality (C:H), with no effect on integrity or availability. No public exploits have been reported, indicating that exploitation is currently theoretical or limited. The vulnerability is categorized under CWE-285 (Improper Authorization), highlighting a failure in enforcing correct access control policies. This issue is particularly relevant for environments where sensitive data is stored on removable media and where macOS devices are used extensively. Organizations relying on macOS systems should be aware of this vulnerability and apply the patch available in macOS Sonoma 14 to prevent unauthorized data access.

For European organizations, this vulnerability poses a risk to the confidentiality of sensitive data stored on removable media connected to macOS devices. Attackers or malicious applications with local access could exploit this flaw to read confidential files without user consent, potentially leading to data leakage or exposure of intellectual property, personal data, or regulated information. This is especially critical for sectors such as finance, healthcare, legal, and government agencies that handle sensitive or regulated data on portable storage. Although exploitation requires user interaction and local access, the risk increases in environments where users frequently connect removable drives or where endpoint security controls are lax. The lack of impact on integrity and availability limits the scope of damage, but unauthorized data disclosure alone can have severe compliance and reputational consequences under regulations like GDPR. The absence of known exploits reduces immediate risk but does not eliminate the need for prompt remediation. Organizations with macOS endpoints should consider this vulnerability in their risk assessments and incident response planning.

The primary mitigation is to update all affected macOS devices to Sonoma 14 or later, where the vulnerability is fixed with improved access checks. Until patching is possible, organizations should enforce strict application control policies to limit which apps can run on macOS endpoints, especially restricting apps that request access to removable volumes. Endpoint protection solutions should be configured to monitor and alert on unusual access to removable media. User education is important to reduce risky behaviors such as running untrusted applications or connecting unknown removable drives. Additionally, implementing device control policies to restrict or log the use of removable storage can reduce the attack surface. For highly sensitive environments, consider disabling or tightly controlling removable media usage on macOS devices. Regular audits of app permissions and system logs can help detect attempts to exploit this vulnerability. Finally, integrating this vulnerability into vulnerability management and patching workflows ensures timely remediation.