Secure Development & Testing

This chapter covers implementing security throughout the development process, ensuring security is built into the device rather than added as an afterthought.

Most security problems in medical devices get baked in during development, long before anyone is thinking about attacks. This chapter shows how to build security into the work itself instead of inspecting it in at the end. It starts with the Secure Product Development Framework that FDA's 2023 premarket guidance expects manufacturers to follow, and explains how security requirements, design reviews, and verification fit inside the design controls you already run under 21 CFR 820.30.

From there it gets practical. The secure coding sections cover the vulnerabilities that show up again and again in device software: buffer overflows in C and C++, injection attacks, hardcoded credentials, and weak cryptography. You'll find concrete guidance on input validation, memory-safe practices, using proven crypto libraries instead of writing your own, error handling that fails to a safe state, and authentication schemes that work in a clinical setting, including emergency access.

Because modern devices are mostly other people's code, often 80 percent or more, a big part of the chapter deals with third-party components: how to vet them before you adopt them, how to build the SBOM that Section 524B requires in formats like SPDX and CycloneDX, and how to keep watching those components for new CVEs after release. The testing sections layer static analysis, dynamic testing, fuzzing, and penetration testing, since each catches problems the others miss.

The chapter closes with build and release security (signed code, hardened build pipelines, protected update channels), the documentation and traceability evidence FDA reviewers look for, and five pitfalls that trip up even experienced teams, starting with security by obscurity. The recurring point: every line of code, every component choice, and every test either strengthens or weakens the device patients will depend on.