SDL Secure Software Development Practices 2 — Questions and Answers
Question 1: Which SDL activity is specifically designed to identify security vulnerabilities by having experts manually examine code without executing it?
- Dynamic analysis
- Fuzz testing
- Static code analysis (Correct answer)
- Penetration testing
Correct answer: Static code analysis
Static code analysis examines source code without executing it to find vulnerabilities like buffer overflows, injection flaws, and insecure API usage.
Question 2: In SDL, what is the primary purpose of an 'abuse case' during requirements gathering?
- To document expected user workflows
- To describe how an attacker might misuse the system (Correct answer)
- To list software defects found in testing
- To specify performance benchmarks
Correct answer: To describe how an attacker might misuse the system
Abuse cases describe malicious or unintended uses of a system, helping teams design defenses against specific attack patterns during early requirements phases.
Question 3: Which cryptographic practice is mandated by SDL to ensure sensitive data remains protected if a single algorithm is broken?
- Using only symmetric encryption
- Implementing cryptographic agility (Correct answer)
- Hardcoding encryption keys in source
- Relying solely on transport-layer security
Correct answer: Implementing cryptographic agility
Cryptographic agility allows systems to swap out algorithms without major redesign, ensuring resilience when cryptographic weaknesses are discovered.
Question 4: During SDL's Verification phase, what does 'attack surface review' primarily assess?
- The number of code lines reviewed
- All user-accessible entry points that attackers could exploit (Correct answer)
- The performance of encryption routines
- Compliance with coding style guidelines
Correct answer: All user-accessible entry points that attackers could exploit
Attack surface review inventories all exposed interfaces, APIs, data inputs, and protocols to ensure unnecessary entry points are eliminated before release.
Question 5: What SDL principle requires that components operate with only the permissions necessary to perform their intended function?
- Defense in depth
- Least privilege (Correct answer)
- Separation of duties
- Security by obscurity
Correct answer: Least privilege
Least privilege limits the access rights of processes and users to the minimum needed, reducing the blast radius if a component is compromised.
Question 6: In SDL threat modeling, what does STRIDE stand for?
- Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, Elevation of privilege (Correct answer)
- System, Threat, Risk, Integrity, Defense, Encryption
- Scanning, Testing, Review, Intrusion, Detection, Evaluation
- Security, Trust, Resilience, Isolation, Detection, Encryption
Correct answer: Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, Elevation of privilege
STRIDE is Microsoft's threat classification model used in SDL to systematically identify six categories of security threats during design.
Question 7: Which SDL practice involves deliberately injecting malformed or random data into application inputs to discover crashes and vulnerabilities?
- Code review
- Threat modeling
- Fuzz testing (Correct answer)
- Security training
Correct answer: Fuzz testing
Fuzz testing (fuzzing) automatically generates unexpected inputs to trigger unhandled errors, crashes, or security vulnerabilities in software.
SDL Secure Software Development Practices 2
Which SDL activity is specifically designed to identify security vulnerabilities by having experts manually examine code without executing it?