Microsoft's Patterns & Practices team has released a new PAG document on threat modeling of web applications. This document includes a description of the threat modeling process and key concepts, the web application security frame, and templates for creating threat models with samples and walkthroughs.
"This guidance presents the patterns & practices approach to creating threat models for Web applications. Threat modeling is an engineering technique you can use to help you identify threats, attacks, vulnerabilities, and countermeasures that could affect your application. You can use threat modeling to shape your application's design, meet your company's security objectives, and reduce risk."
The introduction starts with a description of the threat modeling process and key concepts in creating a threat model.
The five threat modeling steps are:
- Step 1: Identify security objectives. Clear objectives help you to focus the threat modeling activity and determine how much effort to spend on subsequent steps.
- Step 2: Create an application overview. Itemizing your application's important characteristics and actors helps you to identify relevant threats during step 4.
- Step 3: Decompose your application. A detailed understanding of the mechanics of your application makes it easier for you to uncover more relevant and more detailed threats.
- Step 4: Identify threats. Use details from steps 2 and 3 to identify threats relevant to your application scenario and context.
- Step 5: Identify vulnerabilities. Review the layers of your application to identify weaknesses related to your threats. Use vulnerability categories to help you focus on those areas where mistakes are most often made.
The web application security frame is a set of categories used to group common security vulnerabilities for use in reviews of potential threats and for planning countermeasures. Some of the categories include Input and Data Validation, Authentication, Cryptography, Parameter Manipulation, and Exception Management.
The template given is a document template used to track the threat modeling process and record security objectives and describe the deployment scenario.
Read Treat Modeling Web Applications