threat modeling

1. Threat Modelling
Rajeev.P.V
CB.EN.P2CSE13014
Date:26/11/2013

2. Basic definitions
 Threat Agent
Someone who could do harm to a system (also adversary).
 Threat
An adversary’s goal.
 Vulnerability
A flaw in the system that could help a threat agent realize
a threat.
 Asset
Something of value to valid users and adversaries alike.
 Attack
When a motivated and sufficiently skilled threat agent takes
advantage of a vulnerability.

3. Why Threat Modeling?
We must put
appropriate defenses
in our products
Because
attackers
Want to attack
our
application

4. Purpose
Identify threats and vulnerabilities.
Raise security awareness amongst developers.
Improve communication.
Identify areas of the architecture that require
more research etc.

5. Brief overview
 Identify relevant threats and vulnerabilities in the scenario to
help shape the application's security design.
 Input
Use cases
Data flow
Data schemes
Deployment Diagrams
 Output
Threats
Vulnerabilities

6. Threat Modelling Steps
 Step 1: Identify security objectives. Clear objectives help us
to focus the threat modeling activity and determine how much
effort to spend on subsequent steps.
 Step 2: Create an application overview. Itemizing our
application's important characteristics helps us identify
relevant threats.
 Step 3: Decompose your application. A detailed
understanding of the mechanics of our application makes it
easier for us to uncover more detailed threats.

7. Threat Modelling Steps(Cont.)
 Step 4: Identify threats. Use details from steps 2 and 3 to
identify threats relevant to the application scenario and
context.
 Step 5: Identify vulnerabilities. Review the layers of the
application to identify weaknesses related to the threats. Use
vulnerability categories to help focus on those areas where
mistakes are most often made.

8. Step 1: Identify security objectives
 Input
Business requirements
Corporate security policies
 Output
Key security objectives
• Confidentiality
• Integrity
• Availability

9. Step 2: Create an application overview
 Input
Deployment diagrams
Use cases for user types
Functional Specifications
 Output
Scenarios.
Roles (administration, anonymous browsing)
Technologies
Security mechanisms

10. Step 3: Decompose your application
 Input
Deployment diagrams
Use cases
Functional specifications
Data flow diagrams
 Output
Trust boundaries
Entry points
Exit points
Data flows

11. Step 4: Identify threats
 Input
Common threats
 Output
Threat list (the threats that apply to your situation)

12. Step 5: Identify vulnerabilities
 Input
Common vulnerabilities
 Output
Vulnerability list relevant to your situation

13. Thank you……