CVE-2025-43216 is a use-after-free vulnerability classified under CWE-416 that affects Apple Safari across multiple platforms including macOS (Sequoia 15.6), iOS 18.6, iPadOS 17.7.9 and 18.6, watchOS 11.6, tvOS 18.6, and visionOS 2.6. The vulnerability stems from improper memory management when Safari processes maliciously crafted web content, which can lead to an unexpected crash of the browser. This type of vulnerability occurs when a program continues to use memory after it has been freed, potentially causing instability or crashes. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H) indicates that the vulnerability can be exploited remotely over the network with low attack complexity, requires no privileges, but does require user interaction (such as visiting a malicious webpage). The impact is limited to availability, as confidentiality and integrity are not affected. No known exploits have been reported in the wild as of the publication date. Apple has released patches in Safari 18.6 and corresponding OS updates to address this issue by improving memory management to prevent the use-after-free condition. Organizations relying on Safari for web access should apply these updates promptly to avoid potential denial-of-service scenarios caused by browser crashes.

The primary impact of CVE-2025-43216 is on availability, as exploitation leads to an unexpected crash of Safari, potentially causing denial-of-service conditions for users. For European organizations, this can disrupt business operations, especially those relying heavily on Safari for web-based applications or internal portals. While the vulnerability does not compromise confidentiality or integrity, repeated crashes can degrade user productivity and may be leveraged in targeted denial-of-service attacks against critical services accessed via Safari. Organizations in sectors such as finance, government, healthcare, and critical infrastructure that use Apple devices extensively could face operational disruptions. Additionally, the requirement for user interaction means phishing or social engineering could be used to lure users to malicious sites, increasing risk. The absence of known exploits in the wild reduces immediate threat but does not eliminate the risk of future exploitation. Timely patching is essential to mitigate potential impacts.

1. Immediately update Safari to version 18.6 or later and apply all related OS updates (iOS 18.6, iPadOS 17.7.9/18.6, macOS Sequoia 15.6, watchOS 11.6, tvOS 18.6, visionOS 2.6) across all Apple devices within the organization. 2. Implement network-level protections such as web filtering and DNS filtering to block access to known malicious websites that could exploit this vulnerability. 3. Educate users about the risks of interacting with untrusted web content and phishing attempts that could trigger the vulnerability. 4. Employ endpoint detection and response (EDR) solutions to monitor for unusual browser crashes or suspicious activity indicative of exploitation attempts. 5. Regularly audit and inventory Apple devices to ensure all are running supported and patched versions of Safari and OS. 6. Consider deploying browser isolation technologies for high-risk users to contain potential malicious web content. 7. Maintain robust incident response procedures to quickly address any denial-of-service incidents related to browser crashes. These steps go beyond generic advice by focusing on user education, device management, and layered defenses tailored to the nature of this vulnerability.