CVE-2025-43299 is a denial-of-service vulnerability identified in Apple iOS and iPadOS, as well as macOS Sequoia 15.7, Sonoma 14.8, and Tahoe 26. The root cause is insufficient validation of inputs by the operating system when processing certain app-generated requests, categorized under CWE-20 (Improper Input Validation). This flaw allows a malicious or compromised app to cause the device to crash or become unresponsive, effectively denying service to the user. The vulnerability requires local access (AV:L), meaning the attacker must have the ability to run an app on the device, but no special privileges are required (PR:N). User interaction is necessary (UI:R), such as launching or interacting with the malicious app. The scope is unchanged (S:U), indicating the impact is limited to the vulnerable device itself without affecting other system components or networked devices. Apple addressed this issue by improving input validation in iOS and iPadOS 18.7 and corresponding macOS releases. No public exploits have been reported yet, but the vulnerability poses a risk to device availability, especially in environments where device uptime is critical. The medium CVSS score of 5.5 reflects moderate impact primarily on availability, with no confidentiality or integrity loss. This vulnerability highlights the importance of rigorous input validation in mobile OS components to prevent denial-of-service conditions caused by malicious applications.

The primary impact of CVE-2025-43299 is denial of service on affected Apple devices, which can disrupt user productivity and potentially affect business operations relying on iOS and iPadOS devices. Organizations using Apple mobile devices in critical roles—such as healthcare, finance, or government sectors—may face operational interruptions if exploited. Although the vulnerability does not compromise confidentiality or integrity, the loss of availability can hinder communication, access to critical applications, and overall device usability. The requirement for local app execution and user interaction limits remote exploitation, but insider threats or malicious apps distributed through less controlled channels could leverage this flaw. The absence of known exploits reduces immediate risk, but the potential for disruption remains significant, especially in environments with high device usage density. Enterprises managing large fleets of Apple devices may experience increased support costs and downtime if this vulnerability is exploited. Timely patching is essential to maintain device reliability and prevent denial-of-service incidents.

To mitigate CVE-2025-43299, organizations should prioritize updating all Apple iOS and iPadOS devices to version 18.7 or later, as well as updating macOS systems to the specified patched versions. Device management solutions should enforce update policies and monitor compliance to ensure timely deployment. Restrict installation of apps to trusted sources, such as the official Apple App Store, and employ Mobile Application Management (MAM) tools to control app permissions and behavior. Implement user education programs to reduce the risk of interacting with potentially malicious apps. For environments with heightened security requirements, consider application whitelisting and sandboxing techniques to limit app capabilities. Regularly audit installed applications and remove any that are unnecessary or untrusted. Additionally, monitor device logs for unusual crashes or performance degradation that may indicate exploitation attempts. Since no exploits are currently known, proactive patching and app control remain the most effective defenses.