Cybersecurity 101: Secure by Design

In the previous blog post, we explored the scope of cybersecurity as a whole in an application development environment. Today, our focus shifts to examining the role of cybersecurity during the design and planning phases of application development.

In this phase, understanding the importance of threat modeling and secure product development is like making the foundations before constructing a building.

Threat modeling serves as the initial assessment, allowing us to identify potential risks and vulnerabilities early in the process. Meanwhile, secure product development acts as the blueprint for constructing a resilient application.

Threat Modeling

When planning the application, the first goal in Cybersecurity is to identify and record the threats, assess them, and define mitigations. The base requirement for creating a threat model is a mature development lifecycle (SLDC).

The general flow is as follows:

1. When defining the architecture, we take note of the systems in play, their components, data flows, and dependencies.
2. Identify assets: Hardware, personnel, software, etc. Understand what needs protection and who needs access to what.
3. Identify threats: Threats can come from various sources, such as malicious actors, natural disasters, or technical failures. Common threat categories include unauthorized access, data breaches, denial-of-service attacks, and more.
4. Vulnerability Analysis: Identify vulnerabilities in the system that the identified threats could exploit. This involves looking at weaknesses in the system's design, implementation, or configuration.
5. Assess risks and develop mitigation strategies: Evaluate the likelihood and impact of each identified threat. This step helps prioritize which threats pose the most significant risks to the system. A risk assessment typically involves assigning a risk level based on the combination of likelihood and impact. Develop and prioritize mitigation strategies to address identified risks. This could involve implementing security controls, adopting best practices, or redesigning system parts to reduce vulnerabilities.
   

Examples of tools available for threat modeling:

• Threat Modeling Tool from Microsoft
• OWASP Threat Dragon
• An example illustrating the entire process of creating a threat model is presented here.

Secure Product Development

The primary objective of Secure Product Design is to ensure that products meet or surpass the organization’s security requirements throughout the development lifecycle. This requires us to make deliberate security choices to achieve the appropriate level of security We will outline the key principles and areas of focus that define what to watch out for and be mindful of during the design and subsequent phases of software development. Everyone on the team must be familiar with these aspects.

Key Principles to Remember

Least Privilege and Separation of Duties
Users should only possess the minimum access necessary for their assigned tasks, and different individuals must handle distinct tasks to prevent overarching control over all transaction aspects.

Defense-in-Depth
Utilize multiple layers of security controls encompassing physical, network, application, and data layers. The aim is to establish a resilient environment capable of detecting and responding to security incidents.

Zero Trust
Adopt the assumption that all users, devices, and networks are inherently untrusted. Prioritize the verification and authentication of all access requests before granting any form of access.

Security-in-the-Open
Highlight the importance of security in open-source software development. Developers should maintain awareness of security implications, employ secure coding practices, and collaborate closely with security experts.

Areas of focus

Context
Understand the application's role within the organization's ecosystem, the data it contains, and the associated risk profiles. This involves processes such as Threat Modeling and Business Impact Assessment.

Components
Conduct thorough reviews of libraries, components, and services used in the application. Leverage secure design patterns and components, considering licensing, maintenance, and commercial aspects.

Connections
Analyze interactions, data storage mechanisms, and methods of access. Consider the segregation of tiers and data based on security levels and tenant requirements.

Code
Adhere to secure coding practices, encompassing input validation, error handling, authentication, authorization, cryptography, and secure memory management. Additionally, conduct security testing and code reviews while ensuring that the code remains up-to-date with security best practices.

Configuration
Apply the principle of Least Privilege to limit access and permissions. Implement Defense-in-Depth with multiple layers of security controls. Configure systems to be secure by default, safeguard sensitive data, and plan for secure failure.

Security Measures
Incorporate secure communications, such as HTTPS, and regularly update systems. Have a well-practiced security incident response plan and respond promptly to security incidents to minimize potential damage.

Ensuring cybersecurity in application development begins with thorough planning and design. By incorporating threat modeling early on, developers can spot risks and vulnerabilities and take steps to address them.
Sticking to key principles like least privilege, defense-in-depth, and zero trust fosters a proactive security approach throughout development. Developers should focus on understanding the application's context, checking components, securing connections, and following secure coding practices.

Integrating these principles at every stage of development helps build resilient applications that protect against evolving threats. A focus on security incident response ensures swift action in cases of breaches. Ultimately, a secure-by-design approach builds trust with users in our digital world.