CVE-2024-54536 is a vulnerability identified in Apple macOS that allows an application to edit NVRAM (Non-Volatile Random-Access Memory) variables improperly. NVRAM stores critical system settings such as boot arguments, device configurations, and other low-level parameters essential for system operation. The root cause of this vulnerability is insufficient validation of environment variables, which an app can exploit to modify NVRAM variables without proper authorization. This flaw was addressed in macOS Sequoia 15.2 by implementing improved validation mechanisms for environment variables, thereby preventing unauthorized edits to NVRAM. The vulnerability requires the attacker to have local access with low privileges (PR:L), does not require user interaction (UI:N), and affects the integrity (I:H) of the system but not confidentiality (C:N) or availability (A:N). The attack vector is local (AV:L), meaning remote exploitation is not feasible. There are no known exploits in the wild at the time of publication. The vulnerability affects all macOS versions prior to 15.2, though exact affected versions are unspecified. The CVSS v3.1 base score is 5.5, reflecting a medium severity level. This vulnerability could allow malicious applications or users with limited privileges to alter system configurations stored in NVRAM, potentially leading to persistent system misconfigurations or bypassing security controls that rely on these settings.

The primary impact of CVE-2024-54536 is the unauthorized modification of NVRAM variables, which can compromise the integrity of system configurations on macOS devices. Such changes could allow attackers to alter boot parameters, disable security features, or persist malicious configurations across reboots. Although confidentiality and availability are not directly affected, the integrity compromise could facilitate further attacks or system instability. Organizations relying on macOS devices, especially in sensitive environments, risk having critical system settings tampered with by local attackers or malicious applications with limited privileges. This could lead to bypassing security mechanisms, unauthorized persistence, or disruption of normal system operations. Since exploitation requires local access, the threat is more significant in environments where endpoint security is weak or where users may inadvertently run untrusted applications. The absence of known exploits in the wild reduces immediate risk but does not eliminate the potential for future attacks. Overall, the impact is moderate but could escalate if combined with other vulnerabilities or attack vectors.

To mitigate CVE-2024-54536, organizations should promptly update all macOS devices to version Sequoia 15.2 or later, where the vulnerability is fixed. Beyond patching, organizations should enforce strict application control policies to limit the execution of untrusted or unsigned applications that could attempt to exploit this vulnerability. Employ endpoint detection and response (EDR) solutions capable of monitoring and alerting on unauthorized attempts to modify NVRAM or related system settings. Restrict local user privileges to the minimum necessary to reduce the risk of privilege escalation or unauthorized local changes. Regularly audit system configurations and NVRAM variables for unexpected changes, especially on critical systems. Educate users about the risks of running unverified software and the importance of applying system updates promptly. For high-security environments, consider implementing hardware-based security features such as Apple’s Secure Boot and System Integrity Protection (SIP) to further protect against unauthorized system modifications. Finally, maintain robust physical security controls to prevent unauthorized local access to macOS devices.