CVE-2025-43255 is a vulnerability identified in Apple macOS operating systems, specifically addressed in versions Sonoma 14.7.7, Sequoia 15.6, and Ventura 13.7.7. The issue stems from an out-of-bounds read condition caused by insufficient bounds checking in system components accessible to applications. This vulnerability is classified under CWE-125 (Out-of-bounds Read), which can lead to unexpected system termination or crashes when exploited. An application with low privileges (local access) can trigger this flaw without requiring user interaction, potentially causing a denial of service by forcing the system to terminate unexpectedly. The CVSS v3.1 base score is 3.3, indicating low severity, with the vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L, meaning the attack requires local access, low complexity, low privileges, no user interaction, unchanged scope, and impacts only availability. No confidentiality or integrity impacts are noted. No public exploits have been reported, suggesting limited active exploitation. The vulnerability highlights the importance of robust bounds checking in system-level code to prevent stability issues. Apple has released patches in the specified macOS versions to remediate this flaw, and users are advised to update promptly.

For European organizations, the primary impact of CVE-2025-43255 is on system availability. Exploitation can cause unexpected system termination, leading to potential downtime of critical macOS-based workstations or servers. While the vulnerability does not compromise data confidentiality or integrity, repeated or targeted exploitation could disrupt business operations, especially in environments relying heavily on macOS systems for daily tasks. Organizations in sectors such as finance, media, design, and technology that utilize macOS devices may experience productivity losses or service interruptions. Since exploitation requires local access with low privileges, insider threats or compromised user accounts could leverage this vulnerability to cause denial of service. However, the lack of user interaction requirement simplifies exploitation once local access is obtained. The absence of known exploits in the wild reduces immediate risk but does not eliminate the need for vigilance. Overall, the impact is moderate in operational terms but low in terms of security breach severity.

1. Apply the latest Apple macOS updates immediately, specifically versions Sonoma 14.7.7, Sequoia 15.6, and Ventura 13.7.7 or later, which contain the fix for this vulnerability. 2. Enforce strict application installation policies to allow only trusted and verified applications, reducing the risk of malicious apps exploiting this flaw. 3. Limit local user privileges where possible to minimize the attack surface, ensuring users operate with the least privilege necessary. 4. Monitor system logs and crash reports for unusual or repeated system terminations that could indicate exploitation attempts. 5. Implement endpoint protection solutions capable of detecting anomalous application behavior on macOS devices. 6. Educate users about the risks of installing untrusted software and the importance of reporting system instability promptly. 7. In high-security environments, consider using macOS security features such as System Integrity Protection (SIP) and sandboxing to further restrict application capabilities. 8. Maintain regular backups and incident response plans to quickly recover from potential denial-of-service incidents.