CVE-2025-43251 is a medium-severity vulnerability affecting Apple macOS, specifically related to an authorization issue in the Keychain component. The Keychain is a secure storage system used by macOS to store sensitive information such as passwords, certificates, and cryptographic keys. This vulnerability arises from improper state management in the authorization process, which allows a local attacker with limited privileges (low privileges and requiring local access) to gain unauthorized access to Keychain items. The flaw does not require user interaction to exploit and does not impact system integrity or availability but compromises confidentiality by exposing sensitive stored credentials. The vulnerability was addressed in macOS Sequoia 15.6 through improved state management to enforce proper authorization checks. The CVSS v3.1 base score is 5.5, reflecting a medium severity level, with the vector indicating local attack vector, low attack complexity, low privileges required, no user interaction, unchanged scope, and high confidentiality impact. No known exploits are reported in the wild as of the publication date. The underlying weakness is classified under CWE-863 (Incorrect Authorization), indicating that the system fails to properly enforce access controls on sensitive resources.

For European organizations, this vulnerability poses a significant risk to the confidentiality of sensitive information stored in macOS Keychains, including corporate credentials, VPN keys, and certificates used for secure communications. Organizations relying on macOS devices for critical operations, especially in sectors like finance, healthcare, legal, and government, could face unauthorized disclosure of sensitive data if an attacker gains local access to affected machines. Although exploitation requires local access and low privileges, insider threats or attackers who have already compromised a user account could leverage this vulnerability to escalate access to sensitive credentials, facilitating further lateral movement or data exfiltration. The lack of impact on integrity and availability reduces the risk of system disruption but does not mitigate the risk of data breaches. Given the widespread use of macOS in European enterprises and public sector environments, the vulnerability could be leveraged in targeted attacks or espionage campaigns. The absence of known exploits in the wild currently limits immediate risk but does not preclude future exploitation.

European organizations should prioritize updating all macOS devices to version Sequoia 15.6 or later, where the vulnerability is patched. In environments where immediate patching is not feasible, organizations should enforce strict local access controls, including limiting physical and remote access to macOS devices, employing endpoint protection solutions that monitor for suspicious local privilege escalation attempts, and implementing strong user account management to minimize the risk of unauthorized local access. Additionally, organizations should audit Keychain access logs where possible and educate users about the risks of local attacks. Deploying full disk encryption and enabling FileVault can add a layer of protection against unauthorized physical access. Network segmentation and the principle of least privilege should be enforced to reduce the impact of any compromised macOS device. Finally, monitoring for unusual authentication or credential access patterns can help detect exploitation attempts early.