CVE-2025-43478 is a use-after-free vulnerability identified in Apple macOS that allows a malicious application to trigger unexpected system termination, such as a crash or reboot. The root cause is improper memory management where an application may access memory after it has been freed, leading to instability in the operating system. This vulnerability affects unspecified versions of macOS prior to the release of patches in macOS Sonoma 14.8.2 and macOS Sequoia 15.7.2, which include improved memory management to address the issue. Although no known exploits are currently reported in the wild, the flaw could be leveraged by an attacker who can execute a malicious app on the target system. Exploitation does not require user interaction beyond running the app, but it does require the attacker to have the ability to install or run software on the device. The primary impact is on system availability, causing unexpected termination that could disrupt user activities or critical processes. This vulnerability does not directly compromise confidentiality or integrity but could be used as part of a broader attack chain. The lack of a CVSS score necessitates an assessment based on impact and exploitability factors, suggesting a medium severity rating. The vulnerability highlights the importance of memory safety in operating system components and the risks posed by local application execution.

For European organizations, the primary impact of CVE-2025-43478 is operational disruption due to unexpected system crashes or reboots on macOS devices. This can affect productivity, especially in environments where macOS is widely used, such as creative industries, software development, and certain enterprise sectors. While the vulnerability does not directly lead to data breaches or privilege escalation, denial of service conditions can interrupt critical workflows and potentially cause data loss if unsaved work is lost during system termination. Organizations relying on macOS for endpoint computing or specialized applications may face increased support costs and downtime. Additionally, if exploited in targeted attacks, this vulnerability could be used to destabilize systems as part of a larger campaign. The absence of known exploits reduces immediate risk but does not eliminate the threat, particularly in environments where users may install untrusted applications. European entities with strict uptime requirements or regulatory obligations around system availability should prioritize mitigation to avoid compliance issues and operational risks.

1. Immediately update all macOS devices to the latest patched versions: macOS Sonoma 14.8.2 or macOS Sequoia 15.7.2, as applicable. 2. Enforce strict application control policies using Apple’s built-in tools such as Gatekeeper and System Integrity Protection (SIP) to prevent installation or execution of untrusted or unsigned applications. 3. Implement endpoint protection solutions that monitor for anomalous application behavior indicative of exploitation attempts. 4. Educate users about the risks of installing apps from unverified sources and encourage the use of the Mac App Store or trusted enterprise app distribution. 5. Regularly audit macOS devices for compliance with patch levels and application whitelisting policies. 6. For organizations with critical macOS infrastructure, consider network segmentation and limiting exposure of vulnerable devices to reduce attack surface. 7. Maintain up-to-date backups to mitigate potential data loss from unexpected system terminations. 8. Monitor security advisories from Apple and threat intelligence feeds for any emerging exploit activity related to this vulnerability.