CVE-2025-43211 is a vulnerability in Apple Safari caused by improper memory handling during the processing of web content, classified under CWE-770 (Allocation of Resources Without Limits or Throttling). This flaw can be triggered remotely by an attacker crafting malicious web content that, when loaded by Safari, leads to a denial-of-service (DoS) condition by exhausting system resources or causing a crash. The vulnerability affects multiple Apple platforms including Safari 18.6, macOS Sequoia 15.6, iPadOS 17.7.9, iOS 18.6, tvOS 18.6, watchOS 11.6, and visionOS 2.6. Exploitation requires no privileges or user interaction, making it potentially easy to trigger through a malicious webpage or embedded content. The CVSS v3.1 base score is 6.2, reflecting a medium severity level primarily due to the impact on availability without affecting confidentiality or integrity. Apple addressed the issue by improving memory handling in the affected components. No public exploits or active attacks have been reported to date, but the vulnerability poses a risk of service disruption for users of vulnerable Safari versions.

For European organizations, this vulnerability primarily threatens availability by causing Safari or the underlying operating system to crash or become unresponsive. This can disrupt business operations that rely on Safari for web access, including cloud services, web-based applications, and internal portals. Organizations with a large number of Apple devices or those in sectors where Safari is the default browser (e.g., creative industries, education, and government) may experience operational interruptions. While the vulnerability does not compromise data confidentiality or integrity, repeated or targeted DoS attacks could degrade user productivity and potentially impact customer-facing services. Additionally, environments with strict uptime requirements or critical web services accessed via Safari could face reputational and financial consequences if service disruptions occur.

European organizations should prioritize deploying the security updates released by Apple for Safari 18.6 and the corresponding OS versions (macOS Sequoia 15.6, iPadOS 17.7.9, iOS 18.6, tvOS 18.6, watchOS 11.6, visionOS 2.6). Network administrators can implement web filtering to block access to suspicious or untrusted websites that might host malicious content exploiting this vulnerability. Monitoring browser crash logs and unusual resource consumption on Apple devices can help detect potential exploitation attempts. Organizations should also educate users about the risks of visiting untrusted websites and encourage the use of alternative browsers temporarily if patching is delayed. For critical environments, consider deploying endpoint protection solutions capable of detecting abnormal browser behavior. Regular vulnerability scanning and asset inventory to identify affected devices will aid in ensuring comprehensive remediation.