ISC2 CSSLP domain 4: Secure software implementation

Howard Poston
August 26, 2021 by
Howard Poston

The ISC2 issues the Certified Software Security Lifecycle Professional (CSSLP) credential to developers that have demonstrated a full understanding of the secure software development lifecycle. The information tested in the CSSLP is broken up into eight different domains.

The fourth domain of the CSSLP deals with secure software implementation or ensuring that vulnerabilities do not creep into an application as part of the coding or build process. When taking the CSSLP exam, 14% of the applicant’s grade is based upon their knowledge of Domain 4.

What is secure software implementation?

Domains 1-3 of the CSSLP are largely focused on the planning stages of the software-design lifecycle. This domain discusses the important security concerns and considerations that developers should keep in mind while writing the code.

How will secure software implementation help my career?

The software can go wrong in two main ways. One is poor planning; perfectly implementing a poorly designed application will result in an insecure program.

The other is poor implementation. Most exploitable vulnerabilities in an application are created by a failure to follow development best practices, use of code with existing vulnerabilities and more.

If implementation errors are behind most software vulnerabilities, the ability to avoid, identify and fix them is an invaluable skill for a developer. Software security is a growing concern for many organizations due to the rising number of data breaches and the tighter restrictions and higher penalties imposed by new data protection laws. Secure coding is a vital skillset, and demonstrating competency can be essential for landing a position in a security-focused organization.

What’s covered in CSSLP Domain 4 of the exam?

The fourth domain of the CSSLP tests developers on their knowledge of secure coding practices. This includes everything from standards for writing secure code to ensure the security of the build process. The key points covered in Domain 4 of the CSSLP include:

  1. Adhere to relevant secure coding practices: established best practices exist for every component of an application and should be adhered to throughout the development lifecycle. For example, it is important to perform validation and sanitization of user input, handle errors and exceptions correctly and implement logging and auditing securely.
  2. Analyze code for security risks: when possible, it is best to reuse secure code rather than implement new code that may not be correct or lack appropriate security controls. Throughout the development process, code should be tested for vulnerabilities using Static, Dynamic and Interactive Application Security Testing (SAST, DAST and IAST).
  3. Implement security controls: modification of an application’s code can impact the security of the application and its users. File integrity monitoring (FIM), watchdogs and anti-malware solutions should be deployed to help protect against this.
  4. Address security risks: throughout the secure software lifecycle, security risks may be identified for an application. Each of these risks should be analyzed and remediated, mitigated, transferred or accepted based on the corporate security policy and risk appetite.
  5. Securely use third-party code or libraries: the average codebase has 158 vulnerabilities due to the widespread use of insecure third-party code. Secure use of external code requires testing for these vulnerabilities via software composition analysis (SCA).
  6. Securely integrate components: software is a system of systems with multiple different components linked together via interfaces. These components should be integrated securely through the use of trust contracts and security testing and analysis.
  7. Apply security during the build process: during the software build process, code tampering, incorrect compiler switches and other factors can impact the security of the final application. The use of anti-tampering techniques (such as code signing), validation of compiler settings and addressing all compiler warnings is essential to application security.

Getting started with secure software implementation

When it comes to learning about secure coding, a good starting point is where organizations are currently having issues. Third-party risk is a major problem for many companies because developers aren’t verifying the security of third-party code before including it in their applications. Learn how to detect vulnerabilities in your applications (SAST, DAST, IAST, SCA and more), what those vulnerabilities mean and best practices for fixing and avoiding these security mistakes in the future.



Howard Poston
Howard Poston

Howard Poston is a copywriter, author, and course developer with experience in cybersecurity and blockchain security, cryptography, and malware analysis. He has an MS in Cyber Operations, a decade of experience in cybersecurity, and over five years of experience as a freelance consultant providing training and content creation for cyber and blockchain security. He is also the creator of over a dozen cybersecurity courses, has authored two books, and has spoken at numerous cybersecurity conferences. He can be reached by email at or via his website at