Embedded Security Testing Guide for Developers

Get a breakdown of the three essential types of embedded security testing needed to protect critical devices. Our guide provides a practical roadmap for implementing these strategies early to find vulnerabilities faster, ensure compliance, and deliver secure systems with confidence.

Embedded systems power everything from medical devices to automotive control units, making their security paramount. As cyber threats targeting embedded devices continue to evolve, developers must adopt comprehensive security testing strategies that address vulnerabilities throughout the development life cycle.

This guide provides practical implementation guidance for securing embedded systems through static analysis, dynamic testing, and penetration testing approaches.

For more on this topic, explore our resources on integration testing and embedded software testing solutions.

Key Takeaways

Embedded security testing combines three essential methodologies.

1. Static analysis detects code-level vulnerabilities like buffer overflows and hardcoded credentials.
2. Dynamic analysis (fuzz testing) uncovers runtime vulnerabilities by testing system behavior under unexpected inputs.
3. Penetration testing validates security controls through simulated real-world attacks.

Implementing these approaches early in development through shift-left practices reduces remediation costs by up to 100x compared to fixing vulnerabilities post-deployment, while ensuring compliance with critical safety and security standards like ISO 21434 and IEC 62443.

Why Is Securing Embedded Systems So Important But Difficult?

Embedded systems face unique security challenges due to limited resources, long life cycles, and critical safety implications. Unlike traditional software, their constrained environments (processing power, memory, target size) make robust security implementation difficult without performance impact.

Their decades-long life cycles often lack mechanisms for post-deployment security updates. Breaches in safety-critical systems can be catastrophic, endangering lives (automotive) or compromising patient data and treatments (medical devices).

The growing attack surface of IoT devices makes them attractive targets. Regulatory frameworks like the FDA’s cybersecurity guidance, ISO 21434 for automotive, IEC 62443 for industrial automation, and UNECE WP.29 mandate rigorous security practices.

Technical challenges include:

• Limited tooling for specialized platforms
• Physical accessibility for hardware attacks
• Securing hardware-software interfaces
• Extreme difficulty of patching deployed systems

The convergence of information technology (IT) and operational technology (OT) security adds complexity as embedded systems connect to enterprise networks and cloud services—exemplified by automotive cybersecurity challenges.

Understanding what are embedded systems and their constraints is crucial for tailored security testing.

What Are the Three Main Types of Security Testing for Embedded Systems?

Embedded security testing relies on three complementary methodologies:

1. Static analysis examines source code without execution to identify code-level vulnerabilities early.
2. Dynamic analysis tests runtime behavior by monitoring system responses to various inputs, with fuzz testing being a key technique for uncovering crashes and memory corruption.
3. Penetration testing simulates real-world attacks to validate security controls in near-production or deployed configurations.

These approaches address different aspects of system security, reveal distinct vulnerability classes, and provide unique insights.

Regulatory standards like ISO 21434, IEC 62443, and FDA guidance recognize the value of these diverse methodologies. Effective strategies balance these approaches based on the development phase:

• Static analysis is integrated earliest
• Dynamic testing during integration
• Penetration testing later in development or on production systems

Learn more about comprehensive automated testing for embedded systems and application security testing.

Static Analysis

Static application security testing (SAST) identifies security vulnerabilities in embedded source code without executing it. By analyzing code structure, data flow, and control flow, SAST detects patterns associated with exploitable weaknesses early in the development cycle, minimizing remediation costs.

It’s particularly effective at finding common embedded flaws like buffer overflows, integer overflows, insecure cryptographic implementations, hardcoded credentials, insecure random number generation, and race conditions.

• Modern SAST tools map issues to standards like Common Weakness Enumeration (CWE) and CERT C/C++ secure coding standards and support compliance with frameworks like MISRA C/C++ and OWASP.
• For regulated industries, static analysis for DO-178C compliance and similar approaches for automotive, medical, and industrial systems are crucial.
• Integrating SAST into development workflows via IDE plugins, build system integration, and pull request analysis provides real-time feedback and automated checks.
• Managing false positives through severity thresholds and suppression rules is key to effective adoption.

Specialized C/C++ security testing capabilities address low-level memory vulnerabilities and platform-specific concerns in resource-constrained environments.

Dynamic Analysis

Dynamic security testing examines embedded system behavior during execution to reveal runtime vulnerabilities missed by static analysis.

Fuzz testing, a key dynamic approach, sends malformed, unexpected, or random data to systems to discover crashes, memory corruption, and other security issues.

For embedded systems, fuzzing targets various interfaces and protocols, including communication protocols (CAN bus, UART, SPI, I2C), network protocols (TCP/IP, SOME/IP, DDS, wireless), file parsers (firmware updates, configuration files), and command processors.

• Instrumentation strategies like memory sanitizers and bounds checking enhance fuzz testing by detecting subtle memory safety violations and verifying array access.
• Specialized approaches for embedded targets include hardware-in-the-loop configurations and emulation-based fuzzing.
• Runtime analysis for embedded applications complements fuzz testing by detecting memory errors and resource leaks during normal operation.
• Analyzing crash dumps systematically, identifying memory corruption patterns, and developing proof-of-concept exploits are crucial for validating and prioritizing vulnerabilities.
• Techniques like API security testing and fuzz testing apply to embedded APIs, while dynamic application security testing (DAST) validates security in running systems.

Understanding dynamic analysis fundamentals is essential for effective runtime security validation.

Penetration Testing

Penetration testing simulates real-world attacks against embedded systems to validate security controls and identify exploitable vulnerabilities, mirroring adversarial techniques. It encompasses black box testing (no prior knowledge) and gray box testing (with architectural documentation).

Embedded-specific techniques target unique attack surfaces, including hardware interface exploitation (JTAG, serial consoles), firmware extraction and reverse engineering, side-channel attacks (power analysis, EM emissions), communication protocol exploitation, and privilege escalation testing.

• Careful planning is essential for embedded penetration tests, defining rules of engagement, establishing recovery procedures, documenting baseline configurations, and setting time/budget constraints to focus on high-risk vectors.
• Penetration testing and API security approaches validate web services and REST APIs, with API testing with penetration testing capabilities offering specialized tools for embedded web interfaces.
• A comprehensive API testing guide covers relevant methodologies.
• Findings should be documented with proof-of-concept exploits, including vulnerability descriptions, exploitation steps, impact assessments, and remediation guidance.
• Integrating penetration testing with automotive CI/CD DevOps test automation and implementing QA in a CI/CD pipeline enables continuous security validation.

Best Practices for Embedded Security Testing

Effective embedded security testing addresses challenges like limited debugging, resource constraints, complex attack surfaces, and difficulty reproducing issues.

Key best practices include:

• Integrating security validation into development processes—shift left.
• Conducting threat modeling early.
• Performing static analysis on code commits.
• Establishing and enforcing secure coding standards.
• Implementing automated security gates in CI/CD pipelines.
• Conducting security reviews at architectural milestones.

These practices lead to faster vulnerability remediation, reduced security debt, and improved security outcomes. Additionally:

• Regression testing of embedded systems ensures fixes don’t introduce new issues.
• ISO/SAE 21434 compliance requires continuous validation, and understanding threat analysis and risk assessment (TARA) helps prioritize testing.

Implement Security Testing Early With Shift-Left Practices

Shift-left security testing integrates security validation throughout the development life cycle, significantly reducing remediation costs and improving security outcomes by providing developers with immediate feedback as they code.

Practical shift-left practices include:

• Threat modeling during design.
• Static analysis on code commits.
• Establishing secure coding standards with automated enforcement and training.
• Implementing security gates in CI/CD pipelines.
• Conducting security reviews at architectural milestones.
• Providing developer security training.

Technical implementation involves IDE-integrated static analysis for real-time feedback, pre-commit hooks for policy enforcement, pull request analysis for pre-merge reviews, and automated test suites with security-focused cases.

Software compliance testing methods enable early validation against regulatory requirements. Adding static analysis to your security testing toolbox enhances comprehensive strategies.

Organizations adopting shift-left security see earlier vulnerability discovery, minimal remediation costs, improved developer security awareness, and reduced security debt.

Establish Defense-in-Depth Testing Strategies

Defense-in-depth approaches validate multiple layers of security controls such as hardware, firmware, and application. These strategies ensure layered protection, even if one control fails.

Key testing areas include:

• Secure boot mechanisms
• Cryptographic implementations using validated algorithms and proper key management
• Access controls and authentication
• Secure communication channels
• Firmware update security

Testing requires specialized approaches for different layers: hardware security module (HSM) testing for cryptographic operations, firmware security testing for bootloaders and updates, and application-level testing for authentication, authorization, and APIs.

Coordination between functional safety like ISO 26262 and security practices is crucial. It can be achieved through software compliance testing solutions.

Embedded AI security testing addresses emerging challenges. Integration testing is vital to verify that security controls work together effectively across trust boundaries and that multiple defense layers impede adversary progress.

Maintain Continuous Security Validation and Vulnerability Management

Continuous security validation throughout the product life cycle ensures ongoing security posture strength against evolving threats. Effective vulnerability management involves:

• Automated security regression testing
• Continuous scanning of third-party components
• Security patch validation
• Threat intelligence integration
• Security metrics tracking

Technical implementation relies on automation and monitoring infrastructure, including automated security test suites, component vulnerability databases integrated with build systems, and security metrics dashboards.

Threat intelligence feeds prioritize testing based on emerging attack techniques. Foundational practices like unit testing enable rapid execution of security tests, while requirements traceability ensures comprehensive coverage.

Choosing the right SAST solution is important for embedded needs. Organizational practices include security incident response procedures, vulnerability disclosure policies, security testing documentation, and regular security training.

Continuous validation leads to fewer post-release vulnerabilities, faster threat response, and improved security posture over product life cycles.

Get Started With Embedded Security Testing Using Parasoft

Embedded security testing demands comprehensive approaches addressing vulnerabilities across multiple layers and throughout the development life cycle.

The core methodologies offer complementary insights.

• Static analysis for code-level issues
• Dynamic analysis/fuzz testing for runtime problems
• Penetration testing for control validation

Implementing these through shift-left practices, defense-in-depth strategies, and continuous validation ensures robust security, meets regulatory requirements, and reduces remediation costs.

Parasoft provides integrated security testing solutions for embedded systems.

• Parasoft C/C++test offers static analysis, unit testing, and code coverage for embedded C/C++ applications, identifying vulnerabilities and ensuring compliance with standards like CERT C and MISRA C.
• Parasoft’s compliance testing solutions support safety and security standards (ISO 26262, ISO 21434, IEC 62443, DO-178C, FDA guidance) with automated traceability for certification.
• Parasoft SOAtest broadens the security scope beyond the unit and component level by automating API and integration testing. It validates the security of communication channels and data exchanges between embedded system components and connected enterprise or cloud services, a common attack vector in converged IT/OT environments.