CVE-2025-43520 is a memory corruption vulnerability identified in Apple’s operating systems including macOS, iOS, iPadOS, watchOS, tvOS, and visionOS. The flaw arises from improper memory handling that could be exploited by a malicious application to cause unexpected system termination (crashes) or to write arbitrary data into kernel memory. This kernel memory corruption could potentially lead to privilege escalation or system instability. The vulnerability requires local access with low privileges (AV:L/PR:L) and does not require user interaction (UI:N), which means an attacker must already have some level of access to the device but can exploit the flaw without further user action. The scope is unchanged (S:U), indicating the impact is limited to the vulnerable component without affecting other system components or remote systems directly. Apple has fixed this issue in multiple OS releases including macOS Sonoma 14.8.2, macOS Sequoia 15.7.2, iOS 18.7.2, and others, improving memory handling to prevent corruption. The CVSS v3.1 base score is 5.5 (medium severity), reflecting the moderate risk due to the local access requirement and lack of confidentiality or integrity impact, but with a high impact on availability due to potential system crashes. No known exploits have been reported in the wild as of publication, but the vulnerability’s nature makes it a candidate for exploitation in targeted attacks or malware aiming to gain kernel-level control or cause denial of service.

For European organizations, the primary impact of CVE-2025-43520 lies in potential system instability and denial of service on Apple devices, which could disrupt business operations, especially in environments heavily reliant on macOS or iOS platforms. Although the vulnerability does not directly compromise confidentiality or integrity, the ability to write kernel memory could be leveraged in chained attacks to escalate privileges or bypass security controls, increasing the risk of deeper system compromise. Organizations in sectors such as finance, government, healthcare, and critical infrastructure that use Apple devices for sensitive operations may face increased risk if attackers exploit this vulnerability to disrupt services or gain unauthorized control. The requirement for local access limits remote exploitation but insider threats or malware that gains initial foothold could leverage this flaw. Additionally, unexpected system terminations could lead to data loss or interruption of critical workflows. The lack of known exploits currently reduces immediate threat but does not eliminate the risk, especially as attackers often develop exploits post-disclosure.

To mitigate CVE-2025-43520, European organizations should prioritize deploying the official Apple patches released for macOS Sonoma 14.8.2, macOS Sequoia 15.7.2, iOS 18.7.2, and corresponding updates for other affected OS versions. Beyond patching, organizations should enforce strict application installation policies to limit the ability of untrusted or malicious applications to run locally. Implementing endpoint protection solutions that monitor for abnormal kernel memory access or system crashes can help detect exploitation attempts. Restricting local user privileges and employing application whitelisting can reduce the attack surface. Regularly auditing devices for unauthorized software and maintaining robust incident response plans will improve resilience. For high-security environments, consider network segmentation to isolate Apple devices and limit lateral movement if compromise occurs. User education about the risks of installing untrusted applications can further reduce exposure. Finally, maintain up-to-date backups to mitigate potential data loss from unexpected system terminations.