CVE-2025-4003 is a vulnerability identified in the RefindPlus boot manager, specifically version 0.14.2.AB. The flaw exists in the function InternalApfsTranslateBlock within the source file Library/RP_ApfsLib/RP_ApfsIo.c. This function is responsible for translating APFS (Apple File System) blocks, a critical operation for systems utilizing APFS volumes. The vulnerability manifests as a null pointer dereference, which occurs when the function attempts to access or manipulate memory through a pointer that has not been properly initialized or has been set to null. This leads to a crash or denial of service (DoS) condition on the local host. The attack vector requires local access with low privileges (PR:L), and no user interaction is necessary (UI:N). The vulnerability does not affect confidentiality or integrity but results in high impact on availability (VA:H). The CVSS 4.0 base score is 6.8, categorizing it as a medium severity issue. Exploitation requires local access, and no known exploits are currently observed in the wild. A patch identified by commit 4d35125ca689a255647e9033dd60c257d26df7cb has been released to remediate the issue. Since RefindPlus is a boot manager often used in multi-boot or hackintosh environments, this vulnerability could disrupt system boot processes or cause system instability when APFS volumes are involved, potentially impacting system availability and reliability.

For European organizations, the primary impact of CVE-2025-4003 lies in potential denial of service conditions on systems using RefindPlus 0.14.2.AB with APFS volumes. Organizations employing RefindPlus in environments where APFS is used—such as macOS-based systems or hackintosh setups—may experience system crashes or boot failures, leading to operational disruptions. While the vulnerability does not expose sensitive data or allow privilege escalation, the availability impact could affect critical systems, especially in IT departments or development environments relying on multi-boot configurations. This could result in downtime, loss of productivity, and increased support costs. Since exploitation requires local access, the threat is more relevant in scenarios where attackers have some foothold or insider access. The absence of user interaction simplifies exploitation once local access is obtained. Given the medium severity, the risk is moderate but should not be ignored, particularly in sectors where system uptime is critical, such as finance, healthcare, or manufacturing.

To mitigate CVE-2025-4003, European organizations should: 1) Immediately apply the official patch (commit 4d35125ca689a255647e9033dd60c257d26df7cb) to all affected RefindPlus installations to eliminate the null pointer dereference condition. 2) Audit and inventory systems to identify those running RefindPlus 0.14.2.AB, especially those using APFS volumes, to prioritize patching efforts. 3) Restrict local access to systems running RefindPlus by enforcing strict access controls, limiting user accounts with local login privileges, and monitoring for unauthorized access attempts. 4) Implement host-based intrusion detection systems (HIDS) to detect abnormal crashes or boot failures that may indicate exploitation attempts. 5) Educate system administrators and users about the risks of local exploitation and encourage adherence to the principle of least privilege to reduce the attack surface. 6) For environments where patching is delayed, consider temporary workarounds such as disabling or replacing RefindPlus with alternative boot managers that do not exhibit this vulnerability. 7) Maintain up-to-date backups and recovery plans to minimize downtime in case of system crashes caused by exploitation.