CVE-2025-43470 is a security vulnerability identified in Apple macOS that involves improper permission handling related to disk images owned by administrator accounts. Specifically, a standard user—who normally has limited access rights—may exploit this flaw to view files contained within disk images created by an administrator. Disk images in macOS are commonly used for software distribution, backups, or secure storage, and often contain sensitive or privileged data. The root cause is a permissions issue where the system fails to enforce adequate access restrictions on these disk images, allowing lower-privileged users to bypass intended security boundaries. Apple addressed this vulnerability in macOS Tahoe 26.1 by introducing additional restrictions to prevent unauthorized access. The affected versions are unspecified, but the vulnerability was reserved in April 2025 and published in December 2025. There are no known active exploits in the wild, indicating limited or no current exploitation. However, the potential for unauthorized data disclosure exists if an attacker has local access to the system. Exploitation does not require elevated privileges or user interaction beyond access to the disk image, making it a straightforward privilege escalation vector for data exposure. The vulnerability primarily impacts confidentiality, as it allows unauthorized viewing of potentially sensitive administrator files. Integrity and availability impacts are minimal or nonexistent. The lack of a CVSS score necessitates a severity assessment based on impact and exploitability factors.

For European organizations, this vulnerability poses a risk to the confidentiality of sensitive administrative data stored within disk images on macOS systems. If exploited, standard users could access files intended only for administrators, potentially exposing credentials, configuration files, or proprietary information. This could facilitate further attacks, such as privilege escalation or lateral movement within networks. Organizations with mixed user privilege environments, especially those employing macOS in enterprise settings, are at risk. The impact is heightened in sectors handling sensitive data, such as finance, government, healthcare, and technology. While the vulnerability does not directly affect system integrity or availability, the unauthorized disclosure of administrative files could undermine trust and compliance with data protection regulations like GDPR. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially if attackers develop techniques to leverage this flaw. Prompt patching and access control reviews are critical to mitigate potential damage.

1. Apply the macOS Tahoe 26.1 update as soon as possible to ensure the vulnerability is patched. 2. Conduct an audit of disk images on macOS systems, particularly those created or owned by administrator accounts, to verify that permissions are correctly set and that standard users cannot access sensitive files. 3. Implement strict user privilege management policies to limit local access to systems where sensitive disk images are stored. 4. Employ endpoint security solutions that monitor and alert on unusual access to disk images or administrative files. 5. Educate users and administrators about the risks of storing sensitive data in disk images accessible on shared systems. 6. Consider encrypting disk images or sensitive files within them to add an additional layer of protection beyond file system permissions. 7. Regularly review and update access control policies to align with the principle of least privilege. 8. Monitor security advisories from Apple for any updates or additional patches related to this vulnerability.