CVE-2025-43255 is a vulnerability identified in Apple macOS that stems from an out-of-bounds read condition due to inadequate bounds checking in system code. This flaw allows a local application, operating with low privileges, to trigger unexpected system termination, effectively causing a denial-of-service (DoS) condition. The vulnerability is classified under CWE-125 (Out-of-bounds Read), indicating that the application reads memory outside the intended buffer boundaries, which can lead to system instability or crashes. The issue affects multiple macOS versions prior to the patched releases: macOS Sequoia 15.6, macOS Sonoma 14.7.7, and macOS Ventura 13.7.7. Exploitation does not require user interaction but does require local access with limited privileges, meaning an attacker must already have some foothold on the system. The CVSS v3.1 base score is 3.3, reflecting low severity due to the limited impact (availability only) and the attack complexity. No known exploits have been reported in the wild, and no direct patch links were provided, but users are advised to update to the fixed versions. The vulnerability does not compromise confidentiality or integrity but can disrupt system availability by causing crashes or unexpected shutdowns.

The primary impact of CVE-2025-43255 is on system availability, as it allows a local application to cause unexpected termination of macOS, resulting in denial-of-service conditions. For organizations, this could lead to temporary loss of productivity, disruption of critical workflows, or interruption of services running on affected macOS devices. Since exploitation requires local access with low privileges, the threat is more relevant in environments where untrusted or potentially malicious applications can be executed by users, such as shared workstations or developer machines. The vulnerability does not expose sensitive data or allow privilege escalation, limiting its impact on confidentiality and integrity. However, repeated exploitation could degrade user trust and system reliability. In high-security environments, even low-severity DoS vulnerabilities warrant prompt remediation to maintain operational continuity. The absence of known exploits reduces immediate risk but does not eliminate the need for patching.

To mitigate CVE-2025-43255, organizations should promptly apply the official Apple patches available in macOS Sequoia 15.6, Sonoma 14.7.7, and Ventura 13.7.7 or later versions. Until updates are deployed, restrict the execution of untrusted or unnecessary local applications, especially those obtained from outside official channels. Employ application whitelisting and endpoint protection solutions to monitor and control local app behavior. Limit user privileges to the minimum necessary to reduce the risk of exploitation by low-privilege apps. Regularly audit installed software and running processes to detect anomalous activity that could indicate attempts to exploit this vulnerability. Additionally, educate users about the risks of running unverified applications. For organizations with macOS systems in critical roles, consider implementing system monitoring to detect unexpected terminations and automate recovery procedures to minimize downtime.