Supporting the Secure Software Development Lifecycle (SSDLC) in the cloud

March 19th, 2024 Posted in Information Security

This article outlines how to support the Secure SDLC in the cloud, with a particular focus on meeting the unique security challenges posed by cloud software development.  

Businesses are increasingly developing and deploying apps within the cloud, seeking to leverage rapid deployment and scalability, high availability and resilience, and the potential to reduce capital investments required to support back-end infrastructure significantly. 

To design and build high-quality applications, software development teams should look to adopt a systematic and repeatable process for the planning, development, testing and deployment of their applications. The Software Development Lifecycle (‘SDLC’) provides such a framework – defining a set of phases and objectives during planning and design through to creation, testing and deployment. 

Historically, security in application development has been less of a priority – the development process focuses on usability and quick releases. However, this approach leads to a build-up of vulnerabilities and weaknesses in a system (security debt) which are complex and/or costly to address after release.

As a consequence of moving into the cloud, the threats and attack surface of our applications, codebase and infrastructure increases. It becomes increasingly important to identify and address as many vulnerabilities as possible in our applications at each stage of the development lifecycle. Doing so reduces costs, improves the maintainability of the system and code base, and increases the security of our data, ensuring developers are providing high-quality secure applications to clients.  

To achieve this, developers can, and should, integrate security checks at each step of the development lifecycle (known as “shifting security left”). The general framework for incorporating security considerations, assessments and decisions during each phase is known as the Secure Software Development Lifecycle (“SSDLC”).  

The nuances of cloud computing call for reevaluating and adapting traditional SSDLC processes though. You can’t just port the same framework to the cloud and hope it works without adjusting it to cloud-specific challenges. 

What is SDLC and what does secure SDLC change?

The SDLC is a systematic process that aims to develop software in a structured and standardised way. The SDLC has six distinct phases that cover the entire lifecycle of a software application. Each of the phases has its objectives and deliverables to help with scheduling tasks and overall efficiency:

  1. Requirement analysis – Identify and document the needs and expectations of stakeholders to define clear and precise requirements for the application you’re developing
  2. Design – Create a blueprint for your proposed software solution that outlines system architecture, data structures, interfaces, and detailed design specifications to guide the development process.
  3. Implementation (Development) – Translate the design documents into executable software through coding in a chosen programming language(s).
  4. Testing – Verify and validate the software against the requirements to identify and fix defects. This step helps ensure that your application meets all needs and quality standards.
  5. Deployment – Make the software available for use in a live production environment by deploying it to the end-users or target audience (whether that’s internal employees or paying customers).
  6. Maintenance – Ongoing maintenance and updates to the software to fix issues, improve performance, adapt to changes in the environment, or add new features as needed or demanded.

Both the SSDLC and SDLC are very similar concepts. The key to understanding the difference between them is to compare and understand the goals of each framework. Traditionally, the SDLC’s primary goal is to deliver functional, usable, high-quality software that meets specific functional and non-functional requirements. Security may be a consideration but not necessarily a focus or a priority. The SSDLC specifically focuses on integrating and prioritising security considerations and practices into the SLDC, concentrating on the identification and mitigation of risks. 

Where standard SLDC activities would include requirements gathering, design, coding, testing, deployment, and maintenance, the SSDLC seeks to integrate security-specific activities – using security analysis, risk assessments, secure coding principles, threat modelling, and security testing (penetration testing and automated or manual code reviews) to identify and address vulnerabilities and weaknesses as early as possible in the development lifecycle. 

Benefits of adopting SSDLC practices?

Aside from the fact that more secure software increases resilience against attacks adopting the SSDLC also comes with operational efficiencies, cost savings, and more.  

  1. Increased Security: SSDLC practices identify and mitigate security risks early. This proactive approach reduces the likelihood of vulnerabilities in the final application, which gives you more secure software solutions for end users. 
  2. Reduced cost: Detecting security flaws during the design or development phases reduces the need for expensive patches and updates after the software’s release. You may also find our blog on incident response in the cloud useful.
  3. Reduced delays: Integrating security into the development process can actually speed up the release of software. By addressing security concerns early and throughout the development lifecycle, there’s less likelihood of last-minute discoveries that can delay your launch.  
  4. Increased consumer trust: Customers are increasingly concerned about the security of their data. By demonstrating a commitment to security through SSDLC practices, customers feel more confident in the security of the apps you develop.  
  5. Competitive edge: The development supply chain is coming under increased scrutiny for very good reason. Demonstrating a firm commitment to delivering high-quality secure products, evidenced by establishing a comprehensive secure development framework will give your organisation an edge over competitors who do not. 

What does SSDLC look like in a cloud context?

The fundamental phases of the SSDLC remain the same in the cloud—Requirement Analysis, Design, Implementation, Testing, Deployment, and Maintenance—but they are influenced by the characteristics of and services provided by cloud platforms. Here’s a couple of extra bits to consider in a cloud context at each stage:

Requirement Analysis

The fundamental phases of the SSDLC remain the same in the cloud—Requirement Analysis, Design, Implementation, Testing, Deployment, and Maintenance—but they are influenced by the characteristics of, and services provided by, cloud platforms. Here are some examples of security aspects and activities to consider in a cloud context at each stage: 

Requirement Analysis:  

  1. Identify security requirements based on industry standards, regulatory and compliance requirements, and your own organisational policies. 
  2. Threat modelling to identify and evaluate possible threats and develop appropraite countermeasures.  
  3. Classify data based on criticality and apply appropriate protections. Consider data residency and data processing requirements.  
  4. Choose the right cloud deployment model (public, private, or hybrid) based on your business objectives and the security requirements of your application and the data being processed. 

Design

  1. Conduct cloud security architectural reviews, taking into account best practices and deployment guidelines provided by your CSP. 
  2. Designing with cloud-native services and capablities in mind, such as using managed database services, network access controls, micro segmentation, and inbuilt encryption for data.  
  3. Take advantage of cloud services that transfer the security responsiblity to the CSP, such as serverless computing. The cloud-shared responsibility model is an excellent starting point to understanding how the responsibility for the security of cloud assets is split between the client and the cloud provider.  

Implementation

  1. Adopt secure coding practices and practices specific to the cloud environment e.g., leveraging CSP security services such as Azure Key Vault, and Identity and Access Management. 
  2. Utilise cloud-native tools to enhance security in your CI/CD pipeline. Integrate vulnerability scans to identify embedded secrets, dependency issues, and vulnerabilities and misconfigurations in virtual machines and infrastructure as code templates before deployment. 
  3. Utilise strong authentication mechanisms in the cloud like multi-factor authentication to restrict access to your source code and the CI/CD tools to authorised personnel only.  

Testing

  1. Using cloud environments to quickly spin up or down test environments allows for more dynamic and extensive testing scenarios. 
  2. Utilise cloud-native security testing tools for both static and dynamic security testing and configuration auditing (E.g., AWS Config).  
  3. Leverage cloud-native automation tools to conduct continuous security testing and vulnerability scanning. Support automation tools with third-party penetration testing. 

Deployment

  1. Using continuous monitoring solutions for cloud environments to detect and respond to threats in real time. 
  2. Use cloud-native deployment tools such as AWS CloudFormation to securely manage infrastructure as code templates and deploy cloud assets. 
  3. Consider redundancy across multiple regions or availability zones for high availability and disaster recovery. 

Maintenance

  1. Use cloud monitoring tools to provide continuous performance and security monitoring across your cloud environment. 
  2. Regularly scanning cloud-native applications and infrastructure for new vulnerabilities and applying patches or updates as needed.
  3. Implement a comprehensive vulnerability management plan and incident response plan. 

Identifying cloud application security threats 

Understanding and identifying threats your cloud application could face, is a vital part of the secure software development lifecycle. To help get you started, we discuss some key cloud security challenges in this blog.  

We have also identified some useful resources below to get you started on your SSDLC journey: 

Cloud Pen Testing with Evalian

To get the most from cloud pen testing, tailor your penetration testing approach to the specific cloud environment, considering its unique services, configurations, and security features. Consider opting for a dedicated service that specialises in cloud environments to conduct thorough and effective tests of everything from configurations to the code of your cloud-native applications. 

Evalian’s penetration testing service gives you expert testers at a cost-effective price. Not only will you be able to develop more secure apps, but you’ll also be able to give added assurance to your clients, stakeholders, and suppliers that you take security seriously. 

Matt Gerry

Written by Matt Gerry

Matt consults on information and cyber security, including incident response, security awareness and training, security gap analysis and certification advisory. Matt started his career working in large multinationals where he gained experience delivering large system implementations, leading projects, and handling key stakeholder relations. He holds an MSc in Information Security from Royal Holloway, University of London.