CVE-2025-43377 is a vulnerability identified in Apple macOS that stems from an out-of-bounds read condition due to improper bounds checking (classified under CWE-125). This flaw allows a local application with limited privileges to read memory outside the intended buffer boundaries, which can lead to a denial-of-service (DoS) condition by crashing the affected process or the entire system. The vulnerability affects multiple Apple operating systems, including macOS Sequoia 15.7.2, macOS Tahoe 26.1, iOS 18.7.2, and iPadOS 18.7.2. The issue was addressed by Apple through improved bounds checking in these updates. The CVSS v3.1 base score is 5.5 (medium severity), with an attack vector of local (AV:L), low attack complexity (AC:L), requiring low privileges (PR:L), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N, I:N), but high impact on availability (A:H). This means an attacker must have local access and some privileges on the device to exploit the vulnerability, but no user interaction is needed. Exploitation results in denial-of-service, potentially causing system instability or crashes. No known exploits have been reported in the wild, indicating limited active exploitation currently. The vulnerability is significant for environments where macOS devices are used in critical roles, as it can disrupt availability and operational continuity.

For European organizations, the primary impact of CVE-2025-43377 is on system availability. Exploitation can cause denial-of-service conditions on macOS devices, potentially disrupting business operations, especially in sectors relying heavily on Apple hardware such as creative industries, software development, and certain government or educational institutions. While confidentiality and integrity are not directly impacted, repeated or targeted DoS attacks could degrade user productivity and service availability. Organizations with distributed macOS endpoints may face challenges in maintaining uptime and service continuity. The requirement for local access and low privileges means insider threats or compromised user accounts pose the greatest risk. Additionally, environments with lax endpoint security or insufficient patch management are more vulnerable. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

To mitigate CVE-2025-43377, European organizations should prioritize deploying the Apple security updates that address this vulnerability: iOS 18.7.2, iPadOS 18.7.2, macOS Sequoia 15.7.2, and macOS Tahoe 26.1. Beyond patching, organizations should enforce strict application control policies to limit installation and execution of untrusted local applications, reducing the risk of exploitation by low-privilege apps. Implementing endpoint detection and response (EDR) solutions can help identify anomalous app behaviors indicative of exploitation attempts. User privilege management should be tightened to minimize unnecessary local privileges that could be leveraged to trigger the vulnerability. Regular auditing of macOS devices for compliance with security baselines and patch levels is essential. Network segmentation and limiting physical or remote access to macOS endpoints can further reduce risk. Finally, educating users about the risks of installing unauthorized software can help prevent exploitation vectors.