CVE-2025-43299 is a medium-severity vulnerability affecting Apple macOS and related operating systems including iOS and iPadOS. The issue is a denial-of-service (DoS) vulnerability that arises due to insufficient input validation, classified under CWE-20 (Improper Input Validation). An unprivileged app, requiring user interaction to trigger, can exploit this flaw to cause a denial-of-service condition on the affected system. This could manifest as a system crash, freeze, or other disruption of normal operations, impacting availability. The vulnerability affects multiple recent Apple OS versions, including macOS Sequoia 15.7, macOS Sonoma 14.8, macOS Tahoe 26, iOS 18.7, and iPadOS 18.7. Apple has addressed the issue by improving validation mechanisms in these versions. The CVSS v3.1 base score is 5.5, reflecting a medium severity level, with an attack vector of local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is unchanged (S:U), and the impact is limited to availability (A:H), with no impact on confidentiality or integrity. No known exploits are currently reported in the wild. The vulnerability's root cause is improper input validation, which could allow a malicious app to trigger a denial-of-service condition, potentially disrupting user productivity or critical processes on affected Apple devices.

For European organizations, this vulnerability poses a risk primarily to availability of Apple devices used within corporate environments. Organizations relying on macOS, iOS, or iPadOS devices for critical business functions could experience service interruptions if a malicious app exploits this vulnerability. Although the attack requires local access and user interaction, the widespread use of Apple devices in sectors such as finance, media, and technology across Europe means that targeted attacks could disrupt operations or cause reputational damage. The lack of confidentiality or integrity impact limits data breach risks, but denial-of-service conditions could affect endpoint availability, potentially delaying workflows or causing downtime. Enterprises with Bring Your Own Device (BYOD) policies or those that allow installation of third-party apps without strict controls may be more vulnerable. Additionally, organizations in sectors with high regulatory requirements for availability (e.g., healthcare, critical infrastructure) should consider the operational impact of such DoS conditions. The absence of known exploits reduces immediate risk, but the medium severity rating and the potential for disruption warrant proactive mitigation.

European organizations should prioritize updating affected Apple operating systems to the patched versions: macOS Sequoia 15.7, macOS Sonoma 14.8, macOS Tahoe 26, iOS 18.7, and iPadOS 18.7. Beyond patching, organizations should implement strict application control policies to limit installation of untrusted or unverified apps, reducing the risk of malicious apps triggering the vulnerability. Employ Mobile Device Management (MDM) solutions to enforce app whitelisting and restrict user permissions to install software. Educate users about the risks of installing untrusted applications and the importance of avoiding suspicious prompts that may trigger the vulnerability. Monitor endpoint logs for unusual application behavior or crashes that could indicate exploitation attempts. For critical systems, consider network segmentation and limiting local access to Apple devices to reduce exposure. Regularly review and update security policies to incorporate vulnerability management for Apple ecosystems. Since user interaction is required, user awareness training is a key component of mitigation. Finally, maintain an inventory of Apple devices and their OS versions to ensure timely patch deployment and compliance.