IEC 62304 verification and validation activities and existing test case execution against software requirements.
Per-mitigation adversarial test execution: positive tests confirming effectiveness, thwarting attempts to bypass each mitigation, and side-effect checks confirming no new vulnerabilities introduced.
Threat-to-mitigation test matrix with adversarial test results — threat models without traceability to specific mitigation test cases are a major and routine finding.
Maps to
IEC 81001-5-1: §5.7.2 THREAT mitigation testing
Requirement text
The manufacturer shall establish an activity (or activities) for testing the effectiveness of the mitigation for the threats identified and assessed in the threat model. Activities shall include: a) creating and executing adequate testing for each mitigation implemented to address a specific threat, in order to ensure that the mitigation works as designed; b) creating and executing plans for attempting to thwart each mitigation; and c) ensuring that the mitigation does not introduce other vulnerabilities to the design.
Why this clause exists
Security requirements testing confirms that implemented controls work as specified; threat mitigation testing asks whether those controls are actually effective against the threats that motivated them. These are different questions. An authentication control that passes functional requirements testing may fail threat mitigation testing because the threat model identified credential stuffing as an attack vector, and the authentication implementation has no rate limiting that would prevent it. Threat mitigation testing evaluates the security controls that address identified threats, not just whether they function correctly in isolation. IEC 81001-5-1:2021 clause 5.7.2 requires testing specifically against the threat mitigations identified in the threat model — creating a direct link between the threat modeling process and the testing phase. This prevents the scenario where a manufacturer has a detailed threat model and detailed security requirements but tests only the requirements without verifying that the mitigations are effective against the identified threats.
What changed
IEC 81001-5-1:2021 is the first standalone cybersecurity standard purpose-built for health software and medical device software. Published in December 2021, it was adapted from IEC 62443-4-1 (industrial control systems security) to address the unique safety and regulatory context of medical devices — adding health-specific requirements that account for patient safety, clinical workflows, and the manufacturer-HDO relationship.
The standard mirrors IEC 62304's lifecycle structure but adds security-specific activities at every phase — planning, development, testing, release, and maintenance. It requires security risk management to be integrated with ISO 14971 safety risk management, not treated as a separate IT concern. FDA formally recognized it as Consensus Standard 13-122 on December 19, 2022 and references it as providing one acceptable framework for satisfying the cybersecurity requirements of Section 524B(b)(2), which requires manufacturers to design, develop, and maintain processes and procedures to provide a reasonable assurance that cyber devices and related systems are cybersecure.
EU MDR harmonization was originally targeted for May 2024 but postponed to May 2028. Despite this delay, Notified Bodies and Competent Authorities universally recognize it as "state of the art" for health software cybersecurity under MDR GSPR Annex I, Section 17.2. Missing or inadequate cybersecurity documentation is already a top cause of Notified Body major non-conformities for SaMD. A December 2025 Interpretation Sheet (ISH1:2025) clarified software item classification into maintained, supported, and required software categories, affecting risk transfer and post-market obligations.
Common gaps (what we see in audits)
- Threat model mitigations not verified through testing — Threat models identify risks and define mitigations, but testing does not verify that each mitigation is effective. There is no traceability from threat model entries to specific test cases confirming the mitigation works.