Introduction: Threat modeling is a structured approach to identify and prioritize potential security threats to a system, application, or network. It is a proactive measure that helps organizations assess the security of their systems and identify any potential vulnerabilities. By identifying these risks early, organizations can take proactive steps to mitigate them before an attacker takes advantage of them.

Asset Types: When performing a threat modeling exercise, it is important to first identify the assets that need to be protected. These assets can include but are not limited to: • Systems and networks • Applications and services • Data and information • Personnel and users • Infrastructure and facilities

Threat Modeling Basics: Threat modeling involves the following steps: • Identifying assets and their importance • Determining potential threats • Evaluating the likelihood of a threat occurring • Assessing the impact of a threat • Prioritizing threats based on likelihood and impact • Developing and implementing mitigations to mitigate the risk.

Attack Vector: An attack vector is a path or method that an attacker uses to access a system, application, or network. Examples of attack vectors include phishing, malware, and network-based attacks.

Attack Surface: The attack surface refers to the total sum of potential vulnerabilities that exist within a system, application, or network. This includes both the entry points for an attacker and the potential weak spots in the system.

Attack Tree: An attack tree is a graphical representation of the different ways an attacker can access a system, application, or network. It is used to model different scenarios and to prioritize mitigation efforts based on likelihood and impact.

Attack Life Cycle: The attack life cycle refers to the different stages of an attack, including reconnaissance, exploitation, and post-exploitation. Understanding the attack life cycle helps organizations develop mitigations that target specific stages of an attack.

Threat Modeling Tools: There are several tools that can be used to support threat modeling activities. Some of the most used tools include:

• STRIDE Methodology

• DREAD Methodology

• TRIKE Threat Modeling Tool

• Elevation of Privilege Threat Modeling Tool

• Delphi Technique

STRIDE Methodology: The STRIDE methodology is a threat modeling approach that helps identify and categorize potential threats. It is based on the acronym STRIDE, which stands for Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, and Elevation of Privilege.

DREAD Methodology: The DREAD methodology is a threat assessment approach that evaluates the likelihood and impact of potential threats. It is based on the acronym DREAD, which stands for Damage, Reproducibility, Exploitability, Affected Users, and Discoverability.

TRIKE Threat Modeling Tool: TRIKE is a tool used to model and visualize potential threats to a system, application, or network. It provides a visual representation of the different attack scenarios and helps organizations prioritize their mitigation efforts.

Elevation of Privilege Threat Modeling Tool: The Elevation of Privilege Threat Modeling Tool is used to assess the potential for an attacker to gain higher levels of access to a system, application, or network. It helps organizations identify the potential for escalation of privileges and take steps to mitigate these risks.

Delphi Technique: The Delphi Technique is a group-based approach to threat modeling that involves brainstorming potential threats and prioritizing mitigation efforts. It helps organizations obtain consensus on potential.

Common Mistakes in Threat Modeling:

Ignoring assets and their importance: Not identifying the assets to be protected can result in a failure to identify potential threats and vulnerabilities.
Not considering the attack surface: Ignoring the attack surface can result in missing potential vulnerabilities and entry points for an attacker.
Failing to prioritize threats: Not prioritizing threats based on likelihood and impact can result in ineffective mitigation efforts.
Overlooking human factors: Ignoring the role that people play in the attack and defense of a system can result in missed opportunities to improve security.
Focusing too much on technical solutions: Relying solely on technical solutions to mitigate threats can result in an ineffective security strategy.
Correct Questions to Ask in Threat Modeling:

What are the assets to be protected?
What are the potential threats to these assets?
What is the likelihood of each threat occurring?
What is the potential impact of each threat?
What are the entry points for an attacker?
What are the weak spots in the system that an attacker could exploit?
What are the different attack scenarios?
What are the potential mitigations for each threat?
What is the effectiveness of each mitigation?
What is the prioritization of mitigation efforts based on likelihood and impact?
How will the mitigations be implemented and maintained over time?

What is Multilevel Threat Modeling?

Multilevel Threat Modeling is a process of conducting threat modeling at multiple levels of abstraction in an organization's systems, applications, or products. The purpose of multilevel threat modeling is to provide a comprehensive view of the security posture of an organization, considering the interdependencies and relationships between systems.

Multilevel threat modeling starts with high-level modeling, which focuses on identifying the overall threats and risks to the organization, followed by a more detailed analysis of individual systems, applications, or products. This process is repeated as necessary, with each level of detail adding more granularity to the overall threat model.

Multilevel threat modeling provides a more comprehensive view of an organization's security posture, helps to identify potential security gaps, and supports informed decision-making on security investments and mitigation strategies. Additionally, multilevel threat modeling can help to prioritize mitigation efforts, ensuring that resources are allocated to the areas of highest risk.

Threat and Mitigation Catalogs from NIST, ISO, and ENISA

NIST, ISO, and ENISA are three leading organizations in the field of cybersecurity and information security, and each has developed its own catalogs of threats and mitigations.

NIST Threat and Mitigation Catalogs: The National Institute of Standards and Technology (NIST) has published several catalogs of threats and mitigations, including the NIST Special Publication 800-53 (Rev. 4), which provides a comprehensive list of security controls for federal information systems and organizations. This publication includes a catalog of common threats, such as malware, unauthorized access, and denial of service attacks, and corresponding mitigations, such as network segmentation, firewalls, and intrusion detection systems.

ISO Threat and Mitigation Catalogs: The International Organization for Standardization (ISO) has developed a number of standards related to information security, including ISO/IEC 27001:2013, which provides a framework for information security management systems. This standard includes a catalog of common information security risks, such as unauthorized access, data theft, and data corruption, and corresponding mitigations, such as access control, data encryption, and disaster recovery planning.

ENISA Threat and Mitigation Catalogs: The European Union Agency for Cybersecurity (ENISA) has published several catalogs of threats and mitigations, including the ENISA Threat Landscape report, which provides an overview of the current and emerging cyber threats in Europe. This report includes a catalog of common threats, such as phishing, ransomware, and DDoS attacks, and corresponding mitigations, such as security awareness training, network security, and incident response planning.

In summary, these catalogs provide a comprehensive view of the current cybersecurity threat landscape and the recommended mitigations for mitigating those threats. They serve as valuable resources for organizations looking to improve their security posture and protect against potential attacks.

NIST SP 800-154

The National Institute of Standards and Technology (NIST) has published the Special Publication (SP) 800-154, which provides guidelines for conducting threat modeling. The NIST threat modeling approach is a structured method for identifying and prioritizing potential security threats to a system, application, or product, and for developing and implementing mitigations to mitigate those threats. The following steps outline the NIST threat modeling approach:

Initialize: Define the scope of the threat modeling effort, identify stakeholders, and gather relevant information about the system, application, or product being analyzed.
Identify Assets: Identify the assets to be protected, including data, functionality, and infrastructure components.
Identify Threats: Identify potential threats to the assets, including external threats (such as malicious actors) and internal threats (such as human error).
Prioritize Threats: Prioritize the identified threats based on their likelihood and potential impact.
Identify Mitigations: Identify potential mitigations for each threat, including technical solutions, policy changes, and process improvements.
Evaluate Mitigations: Evaluate the effectiveness of each mitigation, including its impact on system performance and its ability to mitigate the threat.
Implement Mitigations: Implement the most effective mitigations, considering any trade-offs between security and other system requirements.
Monitor and Review: Continuously monitor the security posture of the system, application, or product, and review the threat modeling process to identify areas for improvement.
The NIST threat modeling approach is a flexible and adaptable method that can be customized to meet the specific needs of an organization. By following the steps outlined in SP 800-154, organizations can develop a comprehensive view of their security posture and take proactive steps to mitigate potential threats.

What are common threat modeling Mitigations?

Threat modeling mitigations are measures taken to mitigate the potential impact of identified security threats. Common threat modeling mitigations include:

Access control: Restricting access to sensitive information and systems to only those who need it to perform their job functions.
Authentication and authorization: Ensuring that users are who they claim to be and that they have the appropriate level of access to resources.
Data encryption: Encrypting sensitive data to protect it from unauthorized access or theft.
Firewalls and network security: Implementing firewalls and other security measures to prevent unauthorized access to systems and data.
Intrusion detection and response: Detecting and responding to security incidents in a timely manner.
Security awareness training: Providing employees with training on security best practices and the importance of protecting sensitive information.
Incident response planning: Developing a plan to respond to security incidents in a coordinated and effective manner.
Regular software updates and patches: Keeping software up to date to address known security vulnerabilities.
Vulnerability assessment and penetration testing: Regularly testing systems to identify and address vulnerabilities.
Backup and disaster recovery: Having a plan in place to quickly recover from a disaster, such as a fire or cyberattack.
These are just a few examples of the types of mitigations that organizations can implement to mitigate security threats. The specific mitigations will depend on the results of the threat modeling process, including the prioritization of threats and the specific security requirements of the organization.