Medtronic MyCareLink Patient Monitor CVE-2025-4386

Exploitation requires direct physical access to the device's internal UART serial interface - this typically necessitates opening the device enclosure, removing covers, or locating debug connectors inside the casing. The UART interface must be accessible or exposed (not soldered in epoxy or otherwise sealed). The device must be powered on or the attacker must be able to power it on. No authentication is required once the UART prompt is accessed (PR:N/UI:N per CVSS vector). No special deployment configuration is required - the vulnerability exists in default factory settings. Exploitation is limited by: requirement for physical device access, potential for tamper-evident seals or detection, lack of remote accessibility (AV:P prevents network exploitation), and possible alert systems if the device detects unauthorized physical opening.

Physical attack vector (AV:P) with low complexity and no authentication requirement creates a medium real-world risk profile despite the 6.8 CVSS score. The limiting factor is the requirement for physical access to internal hardware - attackers must physically open or disassemble the device to locate and access the UART interface. However, in healthcare environments where devices are accessible to maintenance personnel, custodial staff, or untrusted insiders, this becomes a meaningful insider-threat vector. The lack of authentication (PR:N, UI:N) means once an attacker gains physical access, exploitation is trivial and non-interactive. No active exploitation, KEV status, EPSS score, or public POC data was provided; classification relies on CVSS vector analysis. The high impact ratings (C:H/I:H/A:H) indicate potential for complete device compromise, patient data disclosure, clinical workflow disruption, or malicious firmware modification - all critical in healthcare contexts. Risk is context-dependent: high for facilities with weak physical security or high insider-threat risk; lower for facilities with strict badge access and device audit logs.

An attacker with physical access to a MyCareLink Patient Monitor in a hospital ward uses a laptop and USB-to-UART cable to connect to the internal serial interface, accesses the unprotected login prompt, and gains shell access without authentication. Once in the system, the attacker modifies patient data, disables alarms, or installs persistent malware to exfiltrate sensitive health information over the hospital network. A realistic scenario involves an insider threat (disgruntled IT contractor, visitor with device access, or maintenance worker) rather than an external attacker, given the physical access requirement.