Demystifying Threat Modeling: Understanding the Basics

What is Threat Modeling?

Threat modeling is an analytical process used to assess the security of a system or product and identify potential threats. By utilizing techniques such as interviews, data flow diagrams, and risk analysis, organizations can effectively anticipate and prioritize possible threats. This approach offers valuable insight into the associated security risks of a given system or product.

The process begins by creating an abstract model of the system’s components, services, and data flows, known as the “threat surface.” Analysts can then review this model to identify areas of weakness or vulnerabilities that attackers could exploit. Once these vulnerabilities are identified, appropriate measures like patching, hardening, or implementing security controls can be taken to address them.

Threat modeling plays a crucial role in an organization’s risk management program, allowing them to proactively mitigate potential security issues before they manifest as real problems. It not only helps ensure compliance with governmental regulations but also assists in meeting security and privacy objectives.

The ultimate goal of security threat modeling is to minimize the chances of successful attacks by anticipating potential attack scenarios and increasing awareness of existing threats. By taking proactive steps to protect against these threats, harm can be prevented before it occurs.

Steps in the threat modeling process

Now that we have a fundamental understanding of what threat modeling is and why it’s important, let’s delve deeper into the specific steps involved in the threat modeling process.

1. Identifying Assets and Potential Threats: The initial stage of threat modeling involves the identification of all assets that require protection within the system, including data, hardware, and software. Once these assets have been recognized, potential threats can be identified. These threats may originate from malicious software or code, external networks or users, or other sources.
2. Identifying Attack Vectors and Impact: Now, let’s move on to the next crucial phase: identifying potential attack vectors and assessing their impact on the security of the system. Attack vectors serve as possible entry points for malicious activities, encompassing weak passwords, vulnerable ports, and unpatched systems. It is imperative to evaluate the potential impact of each identified attack vector meticulously.
3. Prioritizing Threats Based on Likelihood and Impact: After identifying the assets and potential sources of threats, it becomes crucial to prioritize the threats based on their probability of occurrence and the impact they can have on the system. When developing countermeasures or mitigation strategies, it is essential to address the most probable and severe threats first.
4. Developing Countermeasures and Mitigation Strategies: The final step in threat modeling involves developing countermeasures or mitigation strategies for the most significant threats identified during analysis. These countermeasures may include enhancing authentication protocols or updating vulnerable systems with the latest software versions. In certain cases, specific mitigation strategies may be necessary, tailored to the type of risk posed by the threat source. For example, limiting access privileges for certain users can effectively reduce potential risks.

Common Threat Modeling Methodologies

STRIDE

STRIDE is a threat model developed by Microsoft engineers as a powerful tool for uncovering vulnerabilities in systems. It primarily operates by analyzing models of the target system, making it highly effective for evaluating individual systems.

The acronym STRIDE represents the following:

• Spoofing: Occurs when a user or program impersonates another entity.

• Tampering: Involves attackers modifying components or code.

• Repudiation: Refers to the absence of proper logging or monitoring of threat events.

• Information Disclosure: Relates to the unauthorized leakage or exposure of data.

• Denial of Service (DoS): Involves overloading services or components to hinder legitimate usage.

• Elevation of Privilege: Occurs when attackers grant themselves additional privileges to gain control over a system.

By employing the STRIDE model, potential threats and vulnerabilities within an environment can be identified, enabling developers and administrators to proactively mitigate the associated risks. The STRIDE threat model offers a systematic and straightforward approach to threat modeling, encouraging users to think comprehensively about potential risks.

PASTA

PASTA threat modeling is a specialized approach that enables the identification of potential threats within a specific object’s scope. It can be applied to various applications, including mobile, web, and Internet of Things, as well as other IT systems.

PASTA, which stands for Process for Attack Simulation and Threat Analysis, is a risk-centric method that prioritizes the highest and most relevant risks impacting businesses. As IT, including software applications and systems, serves the purpose of achieving business goals, this methodology focuses on mitigating risks that could have a detrimental effect.

By utilizing PASTA threat modeling, organizations can pinpoint targeted threats specific to their systems or applications. This approach provides detailed insights into operational risk factors within a defined scope. Furthermore, by prioritizing risks based on potential harm, businesses can bolster their security against external attacks.

In summary, the PASTA threat model offers practical guidance on countering existing threats and mitigating future ones. Regular utilization of these methods ensures the safety of businesses from malicious actors attempting to gain unauthorized control over networks or access sensitive data.

TRIKE

TRIKE, a threat modeling framework utilized in cyber security audits, employs a risk management and defensive approach to assess threats. A distinct threat model is created to support this process.

To begin, the system is set up, and the analyst proceeds to enumerate the actors, assets, expected actions, and rules of the system. This information can be organized in an actor-asset-action matrix, where each row represents an actor and each column represents an asset.

Each cell in the matrix comprises four components for each CRUD action: create, read, update, and delete. For each component, one must indicate whether it allows approved activity, forbids certain actions, or follows predefined rules. Additionally, a rule tree is connected to these activities to provide further mediation.

Next, a data flow diagram (DFD) is constructed, associating components with actors and resources. By carefully examining the DFD multiple times, potential threats can be identified in TRIKE, including vulnerabilities such as denial of service or privilege escalation.

To evaluate the potential danger posed by attacks on a system through CRUD operations, TRIKE implements a five-point scale for each action, based on the probability of occurrence. Lower scores indicate higher levels of risk. Furthermore, attacks are assessed against three dimensions to determine the type of operation they may perform on an object: always, occasionally, or never.

Security Cards

Security cards serve as a powerful tool for identifying potential threats and vulnerabilities. Unlike structured threat models, this methodology relies on brainstorming and creative thinking. By utilizing a deck of 42 cards, security teams can delve into questions about potential attacks and transcend conventional cybersecurity approaches. With these cards, analysts can simulate scenarios, envision how attacks might be executed, and assess their organization’s response.

The security cards method offers numerous advantages. It fosters out-of-the-box thinking in cybersecurity, equips security teams with knowledge on potential threats, and deepens their understanding of threat modeling practices. Moreover, this approach provides analysts with a comprehensive view of attacks from all angles, enabling them to develop effective action plans in the event of an attack.

Notably, security cards can be employed in tabletop gaming and online simulations, making them suitable for organizations and industries dealing with cyber threats and cybersecurity practices.

OCTAVE

The OCTAVE threat model, known as the Operationally Critical Threat, Asset, and Vulnerability Evaluation, is a risk based strategic assessment and planning technique used by organizations to measure their security risks. Developed by the CERT Division of the SEI in 2003 and refined in 2005, OCTAVE focuses on assessing organizational risk while avoiding technological risks.

At its core, OCTAVE comprises three main components: operational risk assessment, security practices, and technology usage. This process can be divided into three distinct phases that enable organizations to effectively evaluate their cybersecurity risk:

1. Building asset-based threat profiles: This phase involves identifying the assets most critical to the organization and the potential threats they may face.

2. Identifying infrastructure vulnerabilities: Here, the information infrastructure is evaluated to uncover any weaknesses or vulnerabilities.

3. Developing a security strategy and plans: In this phase, risks to the organization’s critical assets are identified, and decisions are made on how best to protect them.

The OCTAVE approach also provides guidance on creating a team responsible for executing each of these steps effectively. This team should include representatives from all divisions of the organization, possessing broad knowledge not only about security processes but also about different aspects of the business. By doing so, they can develop a comprehensive threat model that encompasses both security and operational considerations.

Attack Trees

Attack trees have been employed as a standalone technique for threat modeling, standing the test of time. Nevertheless, in recent years, they have gained prominence within frameworks like PASTA, STRIDE, and CVSS (Common Vulnerability Scoring System). These frameworks effectively integrate attack trees with other strategies, such as white box testing, to fortify overall security measures.

By constructing multiple trees for each attacker’s objective, all potential paths to success can be meticulously mapped and examined. This comprehensive approach facilitates the identification of vulnerabilities, the planning of countermeasures, and the detection of any ongoing attacks during the threat modeling process.

The initial step in creating an attack tree is to compile a list of all possible targets an attacker might aim for. Once these objectives are determined, each one should be assigned its own dedicated tree. In cases where complex systems boast numerous components or goals, this methodology may result in the simultaneous creation of multiple attack trees.

Within these trees, nodes indicate either targets or the actions required to reach them and achieve success. Attackers will leverage these paths to navigate through security measures, unless preemptive action is taken. By visualizing all conceivable pathways, organizations can effortlessly identify weak points and devise strategies to safeguard against unwelcome intrusions or malicious software attacks.

Comprehensive List of Threat Modeling Tools

Here’s a comprehensive list of open source and commercial threat modeling tools:

• app.diagrams.net – This tool offers several models to create threat models, making it an excellent choice for threat modeling. It’s a valuable resource that provides enhanced word choice, improved structure, enhanced readability, and eloquence, while still retaining its original meaning.

• Cairis: Launched in 2012, this open-source threat modeling tool is widely recognized as one of the most comprehensive and powerful tools available.

• Deciduous – This web application simplifies the process of creating attack decision trees, as described in the Security Chaos Engineering report.

• Foreseeti – SecuriCAD Vanguard is a cutting-edge Software-as-a-Service (SaaS) that offers attack simulation and automated threat modeling. Users can simulate attacks on a virtual representation of their AWS environment, enabling them to proactively assess and enhance their security measures.

• IriusRisk – IriusRisk is an advanced threat modeling tool that employs an adaptive questionnaire powered by an expert system. This unique approach guides users through a series of simple yet comprehensive questions regarding their application’s technical architecture, planned features, and security context. By utilizing this tool, users can ensure a thorough and efficient assessment of their application’s security.

• MAL – MAL (Meta Attack Language) is a powerful tool utilized in the development of cyber threat modeling systems for specialized domains like SCADA/OT, automotive, and cloud. These cutting-edge systems facilitate the modeling of cyber threats and the simulation of attacks in various environments, including power grids, vehicle platforms, and cloud infrastructures.

• Microsoft Threat Modeling Tool: Users can leverage Microsoft’s threat modeling tool to personalize their experience and harness the capabilities that align seamlessly with their requirements. This tool offers a holistic and intuitive approach to crafting secure systems, ensuring comprehensive design and user-friendliness.

• OWASP Threat Dragon: OWASP Threat Dragon is a powerful open-source tool for creating and managing threat models of applications. It empowers users to effectively analyze and mitigate potential security risks.

• OWASP PyTM – OWASP PYTM offers a powerful threat modeling solution that empowers users to generate a Data Flow Diagram (DFD) and Sequence Diagram. By leveraging Python and the comprehensive pytm framework, users can identify potential threats to their system with ease.

• Raindance – Raindance is a powerful tool that seamlessly integrates Attack Maps into the software development process. By leveraging Raindance, developers can significantly reduce the time and effort required to create these maps, enabling them to efficiently fortify their applications against potential attackers. With Raindance, safeguarding your software has never been easier or more efficient.

• SD elements – SD Elements is a powerful threat modeling tool designed to assist organizations in identifying and prioritizing potential security risks to their systems and applications. It employs a structured methodology to thoroughly analyze system design and architecture, pinpoint potential attack vectors and vulnerabilities, and provide well-informed recommendations for effective mitigation strategies.

• Threatspec – Threatspec is an open-source tool that empowers developers to articulate the security properties of their applications with clarity and conciseness.

• Threatmodeler – ThreatModeler is a robust solution that empowers DevOps teams to safeguard their IT environment and applications through automated threat modeling for mobile and IoT application design. The ThreatModeler platform enables users to effortlessly design, build, and manage their security throughout the entire development and deployment process.

• Threats Manager Studio (TMS) – TMS is an ideal solution for both novice and experienced threat modelers. Its modular design and diverse range of functionalities ensure that users can obtain precisely what they require. Whether you are new to the field or a seasoned professional, TMS can be customized to suit your specific needs.

• Threagile – Threagile is a versatile open-source toolkit that allows for agile and declarative modeling of assets in an architecture through the use of YAML files. When the Threagile toolkit is executed, it automatically performs security checks against the model. The output is a comprehensive report that highlights potential risks and provides mitigation advice. Additionally, the toolkit generates visually appealing data-flow diagrams in formats such as Excel or JSON.

• TicTaaC – TicTaaC, a Threat modeling-as-a-Code (TaaC) solution, effortlessly adheres to DevSecOps principles. It offers seamless integration with CI/CD and a user-friendly console interface. With TicTaaC, you can harness its powerful capabilities for threat modeling without relying on external dependencies. It simplifies chart plotting and ensures a smooth user experience.

• Tutamantic – The Tutamen Threat Model Automator is a powerful tool that empowers security professionals to efficiently and precisely generate threat models. By leveraging common taxonomies and flexible output formats, it simplifies the creation of dynamic threat models that can easily adapt and evolve alongside the design process. With this tool, security professionals can streamline their workflow, ensuring accuracy and agility in their threat modeling endeavors.

• YAKINDU Security Analyst – Yakindu provides Statechart Tools, a powerful modeling tool for developing and analyzing state machines in embedded systems. With this tool, security analysts can thoroughly examine system security protocols, identifying and addressing any potential vulnerabilities.

Conclusion

In conclusion, threat modeling is a crucial analytical process that empowers organizations to proactively identify and address security threats. By creating a comprehensive “threat surface”, analyzing the threat landscape, and implementing effective security controls, organizations can significantly reduce the risk of successful attacks.

At Securinc, our cyber consulting services are dedicated to assisting clients in leveraging threat modeling to enhance their security posture. With our expertise and guidance, organizations can ensure compliance with governmental regulations, meet their organizational objectives, and safeguard their valuable assets from potential cyber threats.