Comparison of STRIDE, DREAD & PASTA

The ever-evolving threat landscape demands constant vigilance. As security professionals, it's our duty to arm ourselves with the understanding of the potential risks and vulnerabilities lurking within our systems to effectively protect our assets. The increasing number of data breaches and cyberattacks in today's digital age highlights the importance of a proactive security approach. Threat modeling is one such approach.

Threat modeling helps identify potential threats to a system and provides a structured approach to mitigate them. But with multiple options out there, how will you know which is the best threat modeling framework for you? Don’t worry, we’re here to help you with that. Whether you're an experienced cybersecurity professional or a business owner looking to improve your organization's security posture, this blog will provide you with a deeper understanding of the strengths and limitations of each framework, helping you make an informed decision about which one to choose.

What is Threat Modeling? How does it relate to Penetration Testing?

Threat modeling is a structured approach to identifying and evaluating potential security threats to a system. It involves analyzing the system's architecture, data flows, and user roles to identify potential attack vectors and threat actors. The goal is to identify and prioritize security risks so that appropriate countermeasures can be implemented to minimize/mitigate them.

Threat modeling and penetration testing are two essential approaches to identifying and addressing security vulnerabilities in software systems. While they share similar goals, they differ in their approach, methods, and scope. Threat modeling seeks to identify potential threats before they can be exploited, while penetration testing assesses the security of a system by attempting to exploit vulnerabilities. Threat modeling is about assessing the overall security posture of a system from a theoretical perspective and mitigating weaknesses, while penetration testing is about manually assessing the security of a system in a more practical sense by simulating attacks.

Ideally, threat modeling should be performed early in the penetration testing process, during the scoping and planning phase. This allows organizations to identify potential attack vectors and prioritize them for testing during the penetration test. By doing so, organizations can ensure that the penetration test is focused on the most critical vulnerabilities and that their resources are being used effectively.

Now that we understand the importance of threat modeling and how it relates to penetration testing, let's dive into some of the popular threat modeling frameworks available for threat modeling: STRIDE, DREAD, and PASTA. Let's take a closer look at these frameworks and how they can help improve security.

STRIDE, DREAD, and PASTA Frameworks

STRIDE

STRIDE stands for Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, and Elevation of Privilege. Each of these categories represents a potential attack vector that can be exploited by threat actors.

• Spoofing: Refers to an attacker impersonating a legitimate user or system to gain access or deceive others.
• Tampering: Involves unauthorized modification of data or systems, such as changing values or altering code.
• Repudiation: Deals with denying an event or action that has taken place, which can be used to hide malicious activity.
• Information Disclosure: Involves exposing sensitive information to unauthorized parties, which can be used to exploit or harm individuals or organizations.
• Denial of Service: Refers to the disruption or prevention of authorized access to systems or resources, often by overwhelming them with requests.
• Elevation of Privilege: Occurs when an attacker gains higher levels of access or privileges than intended, allowing them to perform unauthorized actions or access sensitive data.

The STRIDE framework works by systematically analyzing each of these categories to identify potential threats and vulnerabilities. The framework then categorizes the identified threats into specific threat classes. For example, spoofing attacks involve impersonating another user or system, while tampering involves modifying data in transit or at rest. This is particularly useful when organizations plan to mitigate entire classes of threats by using class-specific controls rather than threat-specific controls. For example, deploying a Web Application Firewall (WAF) can mitigate an entire class of web application vulnerabilities. By analyzing each of these categories, organizations can identify potential threats and prioritize them for mitigation.

Mostly used for application security, STRIDE can also be extended to network security. The STRIDE framework provides a structured and systematic approach to threat modeling. It helps organizations identify potential threats and vulnerabilities in a consistent and repeatable way, which can improve the effectiveness of their security efforts.

However, the STRIDE framework can be time-consuming and resource-intensive. It requires a significant amount of effort to analyze each of the categories and identify potential threats, which can be a challenge for organizations with limited resources.

DREAD

DREAD stands for Damage, Reproducibility, Exploitability, Affected Users, and Discoverability.

• Damage: Refers to the potential impact that a vulnerability could have on the target. The target can be the organization, the system in question, or other users in general.
• Reproducibility: Refers to how easily the vulnerability can be reproduced by an attacker.
• Exploitability: Refers to how easy or difficult it is to exploit the vulnerability.
• Affected Users: Refers to the number of users who could be affected by the vulnerability.
• Discoverability: Refers to how easy or difficult it is to discover the vulnerability.

This framework works by assigning a score of 0-10 to each of the categories to rate the severity of the potential threat. The scores are then added together to provide an overall score, which is used to prioritize which threats to focus on. You can compare DREAD to the Common Vulnerability Scoring System (CVSS) in terms of how it measures the severity of identified threats. Software Secured uses both DREAD and CVSS combined when scoring vulnerabilities.

The DREAD framework can be used to assess the severity of individual threats that have already been identified through the use of other methodologies, such as STRIDE. Once a threat has been identified, DREAD helps to measure its potential severity by assigning scores. Its methodology can provide a quick and effective way to identify and prioritize potential threats and allows organizations to focus on the most critical threats first.

However, the DREAD framework also has some limitations. One such limitation is that it is focused solely on technical threats and does not consider other factors that could impact the severity of a potential threat, such as the impact on business operations or reputation. Additionally, the framework may not provide sufficient detail to fully assess the severity of a potential threat, and the scores assigned to each category may be subjective and vary based on individual perspectives.

PASTA

PASTA stands for Process for Attack Simulation and Threat Analysis. It is a seven-step methodology used to identify, analyze and prioritize threats and attacks in software applications. PASTA framework is comprehensive and focuses on a risk-based approach to threat modeling.

The PASTA methodology follows a seven-step approach for threat modeling:

• Define Objectives: Identify the security objectives and goals of the system being modeled.
• Define Technical Scope: Define the technical scope of the system and its boundaries.
• Decomposition and Analysis: Decompose the system into smaller components and analyze each of them for potential threats.
• Threat Analysis: Identify and prioritize the potential threats and their attack vectors.
• Vulnerabilities and Weaknesses Analysis: Identify and analyze potential vulnerabilities and weaknesses in the system.
• Modeling and Simulation: Create a visual model using diagrams and simulations to assess the system's security posture.
• Risk Impact Analysis: Evaluate the risks associated with identified threats and vulnerabilities and prioritize them for risk mitigation.

PASTA is often used in organizations that have a mature security program in place. It can be used to guide the development of countermeasures to address the identified risks. This framework is flexible, allowing organizations to customize the methodology to meet their specific needs.

PASTA requires a high level of expertise to implement correctly, and it is typically very time-consuming. It is also a complex methodology, which may not be suitable for smaller organizations with limited resources. Additionally, PASTA does not provide specific guidance on how to address the identified risks, which means that additional expertise may be required to develop an effective risk mitigation plan.

Now that we have explored the STRIDE, DREAD, and PASTA threat modeling frameworks, you may be wondering which one is the best fit for your organization. Let’s discuss some key factors to consider when choosing a threat modeling framework and help you make an informed decision.

Which Threat Modeling Framework is Right for You?

Each of the threat modeling frameworks discussed above has its unique features and is best suited for certain types of organizations. The decision of which one to use ultimately depends on your specific needs and goals, such as business goals, the complexity of your system, and available resources. Let’s look into which threat modeling framework is right for you based on the type of organization.

STRIDE

STRIDE is a popular threat modeling framework used by organizations of all sizes. It is best suited for organizations that are starting with threat modeling for the first time. STRIDE is a simple and straightforward framework that can be easily implemented, making it ideal for small businesses and startups. It is also a good fit for organizations that are primarily concerned with software security, as it is designed specifically for this purpose. In addition, STRIDE can be used by organizations that have a limited budget for security, as it does not require expensive tools or software.

DREAD

DREAD proves to be particularly beneficial for organizations that are looking for a structured and quantitative approach to assess vulnerabilities and prioritize their remediation efforts. It fits well within organizations with complex systems and numerous interconnected components but may be challenging for organizations with limited resources as they might find this framework complex or time-consuming. Additionally, as mitigation suggestions are not part of the model, it is best interpreted by experienced security professionals.

DREAD enables you to efficiently prioritize efforts and focus on the vulnerabilities that pose the greatest risk to your organization's assets. Let’s say you are performing an e-commerce platform penetration test. DREAD can be used to prioritize testing efforts by assigning high scores for damage, exploitability, and affected users to vulnerabilities, such as those that allow an attacker to access customer data.

PASTA

PASTA is a comprehensive threat modeling framework that is best suited for large and complex organizations. It is ideal for organizations that have a lot of different assets to protect, such as financial institutions, government agencies, and large corporations. PASTA is a highly customizable framework that allows organizations to tailor their threat modeling process to their specific needs. It is also a good fit for organizations that have a dedicated security team with the necessary expertise to implement a complex threat modeling framework. PASTA is not recommended for small or medium-sized organizations, as it requires a significant investment in time and resources to implement.

PASTA is recommended for established activities, particularly for use in synergy with risk management. For example, when assessing security for an enterprise-level organization, PASTA can identify critical assets such as customer data, financial information, and intellectual property, assess the impact of a breach, and develop a risk management strategy for protecting them.

There are different factors one should consider when choosing a threat modeling framework. Here’s a summary of each of the threat modeling frameworks discussed under different factors.

FactorSTRIDEDREADPASTAComplexitySuitable for simple applications with fewer components.Can be used for systems of any size and complexity but it is best interpreted by experienced security professionals.Ideal for complex applications with a large number of components.Use CaseEffective for early-stage threat modeling.Useful for vulnerability prioritization and risk management.Designed for complete threat modeling lifecycle.OutputProvides high-level identification of potential threats.Provides a quantitative measure of risk.Offers a comprehensive approach to threat modeling.Ease of UseEasy to learn and implement.Requires a moderate level of expertise.More complex to use and requires a higher level of expertise.

Conclusion

When it comes to selecting a threat modeling framework for your organization, it is important to consider various factors such as the size of the organization, complexity, the goals of the threat modeling exercise, and the expertise of the team.

Each of the three frameworks, STRIDE, DREAD, and PASTA, has its strengths and weaknesses. STRIDE is a simple and easy-to-use framework suitable for smaller organizations or those with limited security expertise. DREAD is a great option for organizations with more mature security practices, looking for a comprehensive risk assessment framework. PASTA is ideal for larger organizations that require a more holistic approach and have a dedicated risk management team.

Ultimately, the choice of the framework depends on the specific needs and circumstances of your organization. It is also worth noting that a combination of these frameworks may be used for more effective and comprehensive threat modeling.