Secure SDLC practices in Cybersecurity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does SDLC stand for in software development?

SDLC stands for Software Development Life Cycle. It is a process used to design, develop, and test high-quality software systematically.

beginner

Why is security important in the SDLC?

Security in SDLC ensures that software is protected from threats and vulnerabilities from the start, reducing risks and costs of fixing issues later.

intermediate

Name two key practices in Secure SDLC.

Two key practices are: 1) Conducting threat modeling early to identify risks, and 2) Performing regular security testing throughout development.

intermediate

What is threat modeling in Secure SDLC?

Threat modeling is a process to identify potential security threats and design ways to prevent or reduce their impact before coding begins.

beginner

How does Secure SDLC help reduce costs?

By finding and fixing security issues early in the development process, Secure SDLC reduces expensive fixes after software release and protects against breaches.

What is the main goal of Secure SDLC?

A To build software with security integrated from the start

B To speed up software delivery ignoring security

C To test software only after release

D To outsource security to third parties

Secure SDLC aims to integrate security into every phase of software development to prevent vulnerabilities early.

Which phase in SDLC is best to perform threat modeling?

A After deployment

B During coding only

C During requirements and design

D After testing

Threat modeling is most effective during requirements and design to identify risks before coding starts.

What type of testing is important in Secure SDLC?

A Security testing

B Only performance testing

C No testing needed

D Usability testing only

Security testing helps find vulnerabilities and verify protections throughout development.

Which practice helps reduce security risks in software development?

A Ignoring security requirements

B Regular code reviews with security focus

C Skipping documentation

D Delaying security fixes until after release

Regular security-focused code reviews help catch issues early and improve software safety.

What is a benefit of integrating security early in SDLC?

A More vulnerabilities in production

B Higher cost to fix issues later

C Longer time to market without benefits

D Reduced risk of security breaches

Early security integration reduces risks and helps prevent breaches in the final product.

Explain the main steps involved in Secure SDLC and why each is important.

Think about how security fits into each phase of software development.

Describe how Secure SDLC helps organizations save money and protect users.

Consider the impact of security issues found late versus early.

Practice

1. What is the main goal of Secure SDLC (Software Development Life Cycle)?

easy

A. To focus only on fixing bugs after software release

B. To speed up software development by skipping testing

C. To integrate security measures throughout the software development process

D. To design software without considering user needs

Solution

1. Step 1: Understand the purpose of Secure SDLC

   Secure SDLC aims to include security at every stage of software creation, not just at the end.

2. Step 2: Compare options with this goal

   Only To integrate security measures throughout the software development process describes integrating security throughout the process, which matches the goal.

3. Final Answer:

   To integrate security measures throughout the software development process -> Option C

4. Quick Check:

   Secure SDLC = Integrate security [OK]

Hint: Secure SDLC means adding security from start to finish [OK]

Common Mistakes:

• Thinking security is only for testing phase
• Believing Secure SDLC speeds up development by skipping steps
• Assuming Secure SDLC ignores user needs

2. Which of the following is a correct practice in Secure SDLC during the development phase?

easy

A. Performing static code analysis to find vulnerabilities

B. Ignoring code reviews to save time

C. Skipping security testing until after deployment

D. Allowing unrestricted access to source code

Solution

1. Step 1: Identify secure development practices

   Static code analysis helps find security issues early in development.

2. Step 2: Evaluate each option

   Performing static code analysis to find vulnerabilities is a known secure practice; others ignore security or increase risk.

3. Final Answer:

   Performing static code analysis to find vulnerabilities -> Option A

4. Quick Check:

   Development phase = Static code analysis [OK]

Hint: Use static code analysis during development [OK]

Common Mistakes:

• Skipping code reviews thinking they waste time
• Delaying security testing until after deployment
• Not protecting source code access

3. Consider this simplified Secure SDLC checklist code snippet:

phases = ['Planning', 'Design', 'Development', 'Testing', 'Deployment']
security_checks = {'Planning': True, 'Design': True, 'Development': False, 'Testing': True, 'Deployment': True}
secure_phases = [phase for phase in phases if security_checks.get(phase)]
print(secure_phases)

What will be the output?

medium

A. []

B. ['Planning', 'Design', 'Development', 'Testing', 'Deployment']

C. ['Development']

D. ['Planning', 'Design', 'Testing', 'Deployment']

Solution

1. Step 1: Understand the list comprehension filtering

   The code selects phases where security_checks is True.

2. Step 2: Check each phase's security status

   'Development' is False, so it is excluded; others are True and included.

3. Final Answer:

   ['Planning', 'Design', 'Testing', 'Deployment'] -> Option D

4. Quick Check:

   Filter True phases = ['Planning', 'Design', 'Testing', 'Deployment'] [OK]

Hint: Filter list by True values in dictionary [OK]

Common Mistakes:

• Including phases with False security checks
• Confusing list comprehension syntax
• Assuming all phases are included

4. A developer wrote this code to check if all SDLC phases have security checks:

phases = ['Planning', 'Design', 'Development', 'Testing', 'Deployment']
security_checks = {'Planning': True, 'Design': True, 'Development': False, 'Testing': True, 'Deployment': True}
all_secure = all(security_checks[phase] for phase in phases)
print(all_secure)

What is the output and why?

medium

A. True, because most phases have security checks

B. False, because 'Development' phase lacks security checks

C. Error, because of incorrect dictionary access

D. None, because the variable is not assigned

Solution

1. Step 1: Understand the all() function usage

   all() returns True only if every item is True; here it checks each phase's security status.

2. Step 2: Check security status for each phase

   'Development' is False, so all() returns False.

3. Final Answer:

   False, because 'Development' phase lacks security checks -> Option B

4. Quick Check:

   all() with one False = False [OK]

Hint: all() is False if any item is False [OK]

Common Mistakes:

• Assuming all() returns True if most are True
• Thinking dictionary access causes error here
• Confusing all() with any()

5. You want to improve security in the SDLC by adding automated security testing after development and before deployment. Which practice best fits this goal?

hard

A. Integrate continuous security testing tools in the CI/CD pipeline

B. Perform manual security reviews only after deployment

C. Skip testing to speed up deployment

D. Allow developers to decide if security testing is needed

Solution

1. Step 1: Identify the goal of adding automated security testing

   The goal is to catch security issues early and continuously during development.

2. Step 2: Evaluate options for fitting this goal

   Integrate continuous security testing tools in the CI/CD pipeline uses automated tools integrated in CI/CD, ensuring continuous checks before deployment.

3. Final Answer:

   Integrate continuous security testing tools in the CI/CD pipeline -> Option A

4. Quick Check:

   Automated testing in CI/CD = Best practice [OK]

Hint: Use automated tests in CI/CD for continuous security [OK]

Common Mistakes:

• Relying only on manual reviews after deployment
• Skipping testing to save time
• Leaving security testing optional