CVE-2025-43211 is a medium-severity vulnerability affecting Apple Safari browser and related Apple operating systems including macOS Sequoia, iPadOS, iOS, tvOS, watchOS, and visionOS. The vulnerability arises from improper memory handling when processing web content, which can lead to a denial-of-service (DoS) condition. Specifically, this issue is classified under CWE-770, which relates to allocation of resources without limits or throttling, potentially allowing an attacker to exhaust system resources. The vulnerability does not require user interaction or privileges to exploit, but it does require local access (AV:L) meaning the attacker must have local access to the device. The CVSS v3.1 base score is 6.2, indicating a medium severity with no impact on confidentiality or integrity, but a high impact on availability. The flaw was addressed by Apple in Safari 18.6 and corresponding OS updates released in mid-2025, which improved memory handling to prevent resource exhaustion during web content processing. No known exploits are currently reported in the wild. The vulnerability affects unspecified versions prior to these patches, so any unpatched Apple devices running Safari or the affected OS versions remain vulnerable to potential DoS attacks triggered by malicious web content.

For European organizations, this vulnerability primarily poses a risk of service disruption on Apple devices used within corporate environments. Since the flaw leads to denial-of-service, an attacker could cause Safari or the entire device to become unresponsive by delivering crafted web content, potentially impacting employee productivity or availability of web-based internal tools accessed via Safari. Although it does not compromise data confidentiality or integrity, the availability impact could disrupt critical workflows, especially in organizations relying heavily on Apple hardware and Safari for web access. Sectors such as finance, government, healthcare, and media in Europe that use Apple devices extensively could face operational interruptions. Additionally, organizations with bring-your-own-device (BYOD) policies may see increased risk if employees’ personal Apple devices are targeted. The lack of known exploits reduces immediate risk, but the medium severity and ease of triggering DoS locally warrant prompt patching to avoid potential targeted disruption or denial-of-service attacks in corporate networks.

European organizations should prioritize updating all Apple devices to the patched versions: Safari 18.6, macOS Sequoia 15.6, iPadOS 17.7.9, iOS 18.6, tvOS 18.6, watchOS 11.6, and visionOS 2.6. IT departments should enforce patch management policies ensuring timely deployment of these updates. Additionally, organizations should implement endpoint protection solutions capable of detecting abnormal resource usage indicative of DoS attempts. Network-level controls could include restricting access to untrusted or suspicious websites that might host malicious content triggering this vulnerability. For environments with strict security requirements, consider limiting Safari usage or sandboxing browser processes to contain potential DoS impacts. User education to avoid opening untrusted web content on Apple devices can further reduce risk. Monitoring device logs for crashes or abnormal behavior related to Safari can help detect exploitation attempts early. Finally, organizations should maintain an inventory of Apple devices and verify patch status regularly to ensure comprehensive coverage.