CVE-2025-43251 is a vulnerability in Apple macOS related to an authorization issue that allows a local attacker to gain unauthorized access to Keychain items. The Keychain is a secure storage system used by macOS to store sensitive information such as passwords, private keys, and certificates. The vulnerability arises from improper state management in the authorization logic, classified under CWE-863 (Improper Authorization). This flaw permits a local attacker with low privileges (PR:L) to bypass intended access controls and read Keychain data without requiring user interaction (UI:N). The vulnerability affects macOS versions before Sequoia 15.6, where Apple addressed the issue by improving state management in authorization checks. The CVSS v3.1 base score is 5.5 (medium severity), reflecting the local attack vector, low complexity, and high confidentiality impact but no impact on integrity or availability. No known exploits have been reported in the wild as of the publication date. The vulnerability requires the attacker to have local access to the system but does not require elevated privileges or user interaction, making it a significant risk in environments where multiple users share devices or where local access controls are weak. The flaw could be exploited to extract sensitive credentials, potentially leading to further compromise of user accounts and services relying on Keychain data.

The primary impact of CVE-2025-43251 is the unauthorized disclosure of sensitive credentials stored in the macOS Keychain, which can lead to significant confidentiality breaches. Attackers gaining access to Keychain items may retrieve passwords, private keys, and certificates, enabling lateral movement within networks, privilege escalation, or impersonation of users and services. This can compromise corporate accounts, encrypted communications, and access to critical systems. Since the vulnerability requires only local access with low privileges and no user interaction, it poses a risk in shared or multi-user environments, as well as in scenarios where attackers gain physical or remote access to a macOS device. The lack of impact on integrity and availability means the system’s operation remains unaffected, but the confidentiality breach alone can have severe consequences for organizations, including data leakage, regulatory non-compliance, and reputational damage. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

1. Apply the macOS Sequoia 15.6 update immediately on all affected systems to remediate the authorization issue. 2. Enforce strict local user access controls, limiting the number of users with local login privileges and using strong authentication mechanisms such as biometrics or hardware tokens. 3. Implement full disk encryption and secure boot features to reduce the risk of unauthorized physical access. 4. Regularly audit local user accounts and remove or disable unnecessary accounts to minimize attack surface. 5. Monitor system logs for unusual access patterns to Keychain or local privilege escalations. 6. Educate users about the risks of local access and encourage reporting of lost or stolen devices promptly. 7. Consider deploying endpoint detection and response (EDR) solutions capable of detecting suspicious local activity related to credential access. 8. For high-security environments, consider additional compartmentalization of sensitive credentials outside the Keychain or use hardware security modules (HSMs) where feasible.