CVE-2025-43424 is a vulnerability identified in Apple macOS and related operating systems (iOS and iPadOS) that allows a malicious Human Interface Device (HID) to cause an unexpected process crash. The root cause is insufficient bounds checking in the handling of input from HID devices, classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). This vulnerability can be exploited by connecting a specially crafted malicious HID device to the target system, which then triggers a process crash without requiring any user interaction or privileges. The attack vector is 'Adjacent' (AV:A), meaning the attacker must have local access to the system or be on the same physical network segment to connect the malicious device. The CVSS v3.1 base score is 4.3, indicating medium severity, with no impact on confidentiality or integrity but causing availability disruption (denial of service). The vulnerability affects unspecified versions prior to macOS Tahoe 26.1, iOS 26.1, and iPadOS 26.1, where the issue has been fixed by implementing improved bounds checks. There are no known exploits in the wild at this time. The vulnerability primarily risks denial of service conditions by crashing processes that handle HID input, potentially disrupting user activities or critical applications relying on these inputs.

For European organizations, the primary impact of CVE-2025-43424 is availability disruption due to unexpected process crashes triggered by malicious HID devices. This could lead to denial of service conditions affecting end-user productivity, operational continuity, or critical systems relying on macOS or Apple mobile devices. Sectors with high reliance on Apple hardware, such as creative industries, education, healthcare, and government agencies, may experience interruptions if malicious devices are introduced. The attack requires physical or logical access to connect a malicious HID device, which limits remote exploitation but raises concerns in environments with shared or public access points, such as offices, conference rooms, or public kiosks. While the vulnerability does not compromise data confidentiality or integrity, repeated or targeted exploitation could degrade trust in device stability and availability. European organizations with strict uptime requirements or regulatory obligations around service availability should prioritize patching to avoid potential operational impacts.

1. Apply the latest Apple security updates immediately, specifically macOS Tahoe 26.1, iOS 26.1, and iPadOS 26.1 or later, which contain the fix for this vulnerability. 2. Implement strict physical security controls to prevent unauthorized connection of external HID devices, including USB ports and other input interfaces, especially in sensitive or high-risk environments. 3. Use endpoint security solutions that can monitor and restrict the use of unknown or unauthorized HID devices. 4. Educate users and IT staff about the risks of connecting untrusted peripherals and enforce policies that limit device usage to approved hardware only. 5. Consider deploying device control software that can whitelist approved HID devices and block others. 6. Regularly audit and monitor connected devices to detect any anomalous or unauthorized peripherals. 7. For environments where physical access cannot be fully controlled, consider network segmentation and access controls to limit exposure. 8. Maintain incident response plans that include procedures for handling suspected device-based attacks or disruptions.