CVE-2025-43191 is a medium-severity vulnerability affecting Apple macOS operating systems, specifically addressed in macOS Sequoia 15.6, macOS Sonoma 14.7.7, and macOS Ventura 13.7.7. The vulnerability stems from a path handling issue, classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), which allows an application to cause a denial-of-service (DoS) condition. This issue arises due to insufficient validation of file system paths, enabling a malicious or flawed app to trigger system instability or crash, thereby disrupting normal operations. The CVSS v3.1 base score is 6.2, indicating a medium level of severity. The attack vector is local (AV:L), requiring the attacker to have local access to the system, but no privileges (PR:N) or user interaction (UI:N) are needed. The impact is limited to availability (A:H), with no confidentiality or integrity impact. No known exploits are currently reported in the wild. The vulnerability is mitigated by improved path validation implemented in the latest macOS updates. Since the affected versions are unspecified but patches are available in recent macOS releases, systems running older versions remain vulnerable until updated. This vulnerability could be exploited by malicious local applications or scripts to disrupt service availability on macOS devices.

For European organizations, the primary impact of CVE-2025-43191 is the potential for denial-of-service on macOS endpoints. Organizations relying on macOS devices for critical operations could experience system crashes or service interruptions, leading to productivity loss and potential operational delays. While the vulnerability does not compromise data confidentiality or integrity, the availability impact could affect user experience and business continuity, especially in environments with a high density of macOS users or where macOS systems are integral to workflows. Since exploitation requires local access without privileges, the threat is more relevant in scenarios where untrusted or less controlled applications might be installed or executed, such as in bring-your-own-device (BYOD) environments or shared workstations. The absence of known active exploits reduces immediate risk, but unpatched systems remain susceptible. European organizations with strict uptime requirements or those in sectors like finance, healthcare, or government should prioritize patching to avoid potential service disruptions.

1. Immediate deployment of the latest macOS updates (Sequoia 15.6, Sonoma 14.7.7, Ventura 13.7.7) to all macOS devices to ensure the path validation fix is applied. 2. Implement strict application control policies to limit installation and execution of untrusted or unauthorized applications, reducing the risk of local exploitation. 3. Enforce endpoint security measures such as macOS Gatekeeper and System Integrity Protection (SIP) to prevent execution of potentially malicious code. 4. Conduct regular audits of installed applications and user privileges to minimize the attack surface. 5. Educate users about the risks of installing unverified software and encourage reporting of unusual system behavior. 6. For environments with shared or BYOD devices, consider additional monitoring for abnormal application behavior or system crashes that could indicate exploitation attempts. 7. Maintain robust backup and recovery procedures to mitigate operational impact in case of denial-of-service incidents.