CVE-2025-43412 is a sandbox escape vulnerability in Apple macOS stemming from a file quarantine bypass. The macOS sandbox is a security mechanism designed to restrict app capabilities and isolate them from critical system resources and user data. This vulnerability allows an application, running with limited privileges, to bypass these sandbox restrictions and potentially execute code or access resources outside its confined environment. The root cause is insufficient validation of quarantined files, which are typically marked by macOS to prevent untrusted code execution. Apple addressed this issue by implementing additional checks in the quarantine mechanism in macOS Sequoia 15.7.2, Tahoe 26.1, and Sonoma 14.8.2. The CVSS 3.1 score of 6.3 reflects a medium severity, with an attack vector requiring local access (AV:L), low attack complexity (AC:L), low privileges (PR:L), and no user interaction (UI:N). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially compromised component. The impact includes limited confidentiality, integrity, and availability losses (C:L/I:L/A:L). Although no exploits are currently known in the wild, the vulnerability could be leveraged by attackers who have gained local access to escalate privileges or move laterally by escaping sandbox constraints. This vulnerability is classified under CWE-284 (Improper Access Control), highlighting the failure to enforce proper security boundaries. Organizations running affected macOS versions should apply the provided patches promptly to mitigate the risk.

For European organizations, this vulnerability poses a risk primarily to environments where macOS devices are used, including corporate laptops, developer machines, and specialized workstations. A successful sandbox escape could allow malicious apps or attackers with local access to bypass security controls, access sensitive data, or execute arbitrary code with elevated privileges. This could facilitate further compromise of enterprise networks, data exfiltration, or disruption of services. Sectors such as finance, government, and technology, which often use macOS systems and handle sensitive information, are particularly at risk. The medium severity indicates that while the vulnerability is not trivially exploitable remotely, it can be leveraged in targeted attacks or combined with other vulnerabilities for more severe outcomes. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure. Failure to patch could lead to increased exposure to insider threats or malware that exploits sandbox escapes to evade detection and containment.

European organizations should implement the following specific mitigations: 1) Immediately update all macOS devices to the fixed versions: Sequoia 15.7.2, Tahoe 26.1, or Sonoma 14.8.2 or later. 2) Enforce strict application whitelisting and limit installation of untrusted or unsigned applications to reduce the risk of malicious apps exploiting the vulnerability. 3) Employ endpoint detection and response (EDR) solutions capable of monitoring sandbox escape attempts and anomalous behaviors on macOS devices. 4) Restrict local user privileges and implement least privilege principles to minimize the impact of local exploits. 5) Conduct regular audits of macOS systems to identify outdated versions and non-compliant devices. 6) Educate users about the risks of running untrusted software and the importance of applying updates promptly. 7) Monitor internal network activity for lateral movement indicators that could result from sandbox escape exploitation. These steps go beyond generic patching advice by focusing on reducing attack surface and improving detection capabilities specific to macOS environments.