CVE-2025-24109 is a critical security vulnerability identified in Apple macOS operating systems, specifically addressed in versions Ventura 13.7.3, Sequoia 15.3, and Sonoma 14.7.3. The root cause is a downgrade issue related to code-signing enforcement, which previously allowed malicious or unauthorized applications to bypass security restrictions and access sensitive user data. Code-signing is a fundamental security mechanism in macOS that ensures only trusted applications can execute with certain privileges. The downgrade flaw permitted an attacker to circumvent these protections by exploiting weaker or older code-signing policies, effectively enabling unauthorized data access without requiring any privileges, user interaction, or authentication. The vulnerability is classified under CWE-200 (Exposure of Sensitive Information), indicating that confidential data could be disclosed to unauthorized parties. The CVSS 3.1 base score of 9.8 reflects the vulnerability's critical nature, with network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). Although no known exploits have been reported in the wild yet, the severity and ease of exploitation make it a significant threat. The vulnerability affects all macOS systems prior to the patched versions, potentially exposing sensitive user data such as credentials, personal files, or system information to malicious applications.

For European organizations, this vulnerability poses a severe risk of data breaches and unauthorized access to sensitive information on macOS devices. Organizations relying on Apple hardware for critical operations, development, or user endpoints could face confidentiality compromises, leading to intellectual property theft, privacy violations, or regulatory non-compliance under GDPR. The integrity and availability of systems could also be impacted if attackers leverage this access to deploy further malware or disrupt services. Given the high CVSS score and no requirement for privileges or user interaction, attackers could remotely or locally deploy malicious apps to exploit this flaw. This could affect sectors with high macOS usage such as technology companies, creative industries, research institutions, and government agencies. The potential for widespread impact is significant, especially if attackers develop exploits targeting this vulnerability. The absence of known exploits currently provides a window for proactive defense but also underscores the urgency of patching.

European organizations should immediately prioritize patching all affected macOS systems to versions Ventura 13.7.3, Sequoia 15.3, Sonoma 14.7.3, or later. Beyond patching, organizations should implement strict application whitelisting and enforce code-signing policies to prevent untrusted applications from executing. Endpoint detection and response (EDR) solutions should be configured to monitor for anomalous application behavior indicative of exploitation attempts. Network segmentation can limit exposure of sensitive systems running macOS. Regular audits of installed applications and system integrity checks can help detect unauthorized changes. User education should emphasize the risks of installing unverified software. Additionally, organizations should review and tighten permissions and access controls on sensitive data to minimize impact if exploitation occurs. Incident response plans should be updated to include scenarios involving macOS data exposure. Collaboration with Apple support and threat intelligence sharing within European cybersecurity communities can enhance preparedness.