CVE-2025-43185 is a vulnerability in Apple macOS identified as a downgrade issue involving code-signing restrictions. Code-signing is a security mechanism that ensures only trusted applications run on the system by verifying their digital signatures. This vulnerability allowed an attacker to bypass or downgrade these code-signing checks, enabling a malicious or unauthorized app to access protected user data that should normally be inaccessible. The flaw was addressed in macOS Sequoia 15.6 by implementing additional code-signing restrictions to prevent such downgrade attacks. The CVSS 3.1 base score is 5.5 (medium), with an attack vector of local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), and high confidentiality impact (C:H) but no impact on integrity (I:N) or availability (A:N). The vulnerability is categorized under CWE-347, which relates to improper verification of cryptographic signatures. No known exploits have been reported in the wild, but the potential for unauthorized data access makes it a significant concern. The vulnerability affects unspecified macOS versions prior to Sequoia 15.6, emphasizing the importance of timely patching. This issue highlights the risks associated with downgrade attacks on security mechanisms like code-signing, which can undermine system trust and data protection.

For European organizations, this vulnerability poses a risk to the confidentiality of sensitive user data stored or processed on macOS devices. Sectors such as finance, healthcare, government, and critical infrastructure that rely on macOS for endpoint computing could face data leakage or unauthorized data access if exploited. Although exploitation requires local access and user interaction, social engineering or malware delivery could facilitate this. The absence of integrity or availability impact limits the threat to data exposure rather than system disruption. However, the potential exposure of protected data could lead to regulatory non-compliance under GDPR, reputational damage, and financial losses. Organizations with remote or hybrid workforces using macOS devices are particularly at risk if endpoint security controls are weak. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure. Therefore, European organizations must act proactively to mitigate potential breaches and comply with data protection regulations.

1. Immediately update all macOS devices to macOS Sequoia 15.6 or later, where the vulnerability is patched. 2. Enforce strict endpoint security policies that limit installation of untrusted applications and monitor for unauthorized code-signing bypass attempts. 3. Implement application whitelisting and use Apple’s built-in security features such as Gatekeeper and System Integrity Protection (SIP) to reduce risk. 4. Educate users about the risks of interacting with untrusted applications or links to minimize social engineering vectors. 5. Employ endpoint detection and response (EDR) solutions capable of detecting anomalous behaviors related to code-signing violations or unauthorized data access. 6. Regularly audit macOS devices for compliance with security policies and verify that all systems are running supported, patched versions. 7. For sensitive environments, consider restricting local user privileges and applying network segmentation to limit lateral movement if exploitation occurs. 8. Monitor security advisories from Apple and threat intelligence sources for any emerging exploit reports related to this CVE.