CVE-2025-4394 is a vulnerability identified in the Medtronic MyCareLink Patient Monitor models 24950 and 24952, specifically affecting versions prior to June 25, 2025. The core issue is the use of an unencrypted filesystem on the device's internal storage, which results in cleartext storage of sensitive information (CWE-312). This vulnerability allows an attacker with physical access to the device to read and modify files stored on the internal filesystem without any encryption or protection. Because the device is a patient monitor, the data stored may include sensitive health information, device configuration, and potentially authentication or operational parameters. The vulnerability has a CVSS v3.1 base score of 6.8, indicating a medium severity level. The attack vector is physical access (AV:P), with low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:N). The impact is high on confidentiality, integrity, and availability (C:H/I:H/A:H), meaning that an attacker can fully compromise the device's data and functionality once physical access is obtained. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability is significant because it exposes sensitive patient data and device integrity to compromise, which can lead to incorrect monitoring, false alarms, or even patient harm if the device is manipulated. The lack of encryption on stored data is a critical design flaw in a medical device that handles sensitive health information and is expected to comply with strict data protection regulations.

For European organizations, particularly healthcare providers and hospitals using Medtronic MyCareLink Patient Monitors, this vulnerability poses a substantial risk. The exposure of sensitive patient health data violates GDPR requirements for data confidentiality and protection. Unauthorized modification of device files could lead to incorrect patient monitoring, potentially endangering patient safety and leading to liability issues. The physical access requirement limits remote exploitation but does not eliminate risk, as devices are often deployed in semi-public or shared environments where unauthorized personnel might gain access. Additionally, the integrity and availability impact could disrupt clinical workflows and emergency responses. This vulnerability could also undermine trust in medical device security, prompting regulatory scrutiny and potential fines. The lack of encryption on stored data may also affect compliance with the EU Medical Device Regulation (MDR) and related cybersecurity standards for medical devices.

1. Immediate physical security controls: Ensure that patient monitors are deployed in secure, access-controlled environments to prevent unauthorized physical access. 2. Device inventory and monitoring: Maintain an accurate inventory of affected devices and monitor for any signs of tampering or unauthorized access. 3. Firmware updates: Engage with Medtronic for firmware patches or updates that implement encryption or secure storage mechanisms; prioritize applying these updates once available. 4. Data access controls: Limit access to the devices to authorized personnel only and implement strict operational procedures for handling and maintaining the devices. 5. Data encryption at rest: Advocate for or implement additional encryption layers where possible, such as network-level encryption or secure gateways that minimize sensitive data exposure on the device itself. 6. Incident response planning: Prepare for potential incidents involving device compromise, including patient data breach notifications and clinical impact assessments. 7. Regulatory compliance review: Conduct audits to ensure that device usage and data handling comply with GDPR and MDR requirements, and document mitigation efforts accordingly.