CVE-2025-43251 is a vulnerability identified in Apple macOS that allows a local attacker to gain unauthorized access to Keychain items due to an authorization issue involving improper state management. The Keychain is a critical macOS component responsible for securely storing passwords, certificates, and other sensitive credentials. The vulnerability arises because the system fails to properly enforce authorization checks when accessing Keychain items, enabling a local attacker with limited privileges (PR:L) to bypass these controls. Notably, exploitation does not require user interaction (UI:N), increasing the risk of stealthy attacks. The vulnerability affects unspecified versions of macOS prior to Sequoia 15.6, where Apple addressed the issue by improving state management and authorization logic. The CVSS v3.1 base score is 5.5 (medium severity), reflecting high impact on confidentiality (C:H) but no impact on integrity or availability (I:N/A:N). The attack vector is local (AV:L), with low attack complexity (AC:L), and privileges required are low (PR:L). No known exploits have been reported in the wild to date. The underlying weakness corresponds to CWE-863 (Incorrect Authorization). This vulnerability could allow attackers to extract sensitive credentials from the Keychain, potentially leading to further compromise of user accounts, encrypted data, or network resources. The fix requires updating to macOS Sequoia 15.6 or later, which implements improved authorization state management to prevent unauthorized Keychain access.

For European organizations, this vulnerability poses a significant risk to the confidentiality of sensitive credentials stored on macOS devices. Organizations relying on macOS endpoints for accessing corporate resources, email, VPNs, or encrypted storage could have their credentials exposed if an attacker gains local access. This could lead to lateral movement within networks, unauthorized data access, or escalation of privileges. Sectors such as finance, government, technology, and healthcare, which often use macOS devices and handle sensitive data, are particularly at risk. The local attack vector means that physical access or prior compromise of a low-privilege account is necessary, limiting remote exploitation but increasing risk from insider threats or compromised endpoints. The absence of user interaction requirement facilitates stealthy attacks. Although no known exploits exist yet, the medium severity score and potential impact on confidentiality necessitate prompt mitigation to prevent credential theft and subsequent attacks.

1. Immediately update all macOS systems to version Sequoia 15.6 or later, where the vulnerability is patched. 2. Enforce strict local access controls and limit the number of users with local access to sensitive macOS devices. 3. Implement endpoint detection and response (EDR) solutions capable of monitoring suspicious local access or attempts to access Keychain items. 4. Use full disk encryption and strong user authentication to reduce the risk of unauthorized physical access. 5. Regularly audit macOS devices for unauthorized accounts or software that could facilitate local attacks. 6. Educate users about the risks of local attacks and the importance of securing their devices physically and logically. 7. Employ multi-factor authentication for critical services to mitigate the impact of credential exposure. 8. Monitor logs for unusual access patterns or privilege escalations on macOS endpoints. 9. Consider restricting the use of macOS devices for highly sensitive operations until patched.