OWASP Threat Dragon
What is Threat Dragon?
OWASP Threat Dragon is a tool used to create threat model diagrams and to record possible threats and decide on their mitigations.
TD is both an online threat modelling web application and a desktop application. It includes system diagramming as well as a rule engine to auto-generate threats and their mitigations. The focus of TD is on great UX, a powerful rule engine and alignment with other development lifecycle tools.
- OWASP PyTM (Pythonic Threat Modeling)
- OWASP Threat Model Cookbook
- Threat Modeling OWASP Cheat Sheet
- OWASP Threat Model Project
- OWASP Threat Model Project (old pages)
Many thanks to these companies for donating various projects to Threat Dragon :
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Threat modelling is widely regarded as a powerful way to build security into the design of applications early in the development lifecycle. At its best, it is especially good for
- Ensuring defence-in-depth
- Establishing consistent security design patterns across an application
- Flushing out security requirements and user stories
However, effective adoption by organisations can be difficult. Reasons for this include:
- There are no cross-platform, free tools (that I am aware of)
- The usability of existing tools is not great - productivity for the team is therefore poor, especially in the early stages of adoption
- The learning curve for teams is steep - threat modelling often ends up being left to a small “expert” subset of a team and ignores the valuable perspectives from the wider team
- Integration with other development lifecycle tools (e.g. issue tracking tools) is poor - leading to models being ignored
OWASP Threat Dragon addresses this by providing a free, open-source, threat modelling web application for teams implementing the STRIDE approach. The key areas of focus for the tool is:
- Great UX - using Threat Dragon should be simple, engaging and fun
- A powerful threat/mitigation rule engine - this lowers the barrier to entry for teams and allow non-specialists to contribute
- Integration points with other development lifecycle tools - when implemented this will ensure that models slot easily into the development lifecycle and remain relevant as the project evolves
Great user experience is one of the key goals for the project and to get that right it needs some users! If you would like to try the tool out, that would be great. A working prototype can be found at:
The desktop variant installers for borh Windows and OSX, aas well as .rpm / .deb packages for Linux, can be downloaded from:
To help you get started, take a look at the (draft) docs:
Coding help of any kind is always welcome. The project builds easily (let us know if you have any problems) so getting up and running should be simple.
Threat rule engine
Q1: Hold on…isn’t this the same as Mozilla’s SeaSponge?
Q2: What browsers can be used for Threat Dragon?
A2: Threat Dragon has been tested on these browsers, but there are certainly more.
|Windows||Edge||Microsoft Edge 38 for Windows 10|
|Windows||IE||Internet Explorer 11 for Windows 10|
|Linux||Abrowser||Mozilla 68.0.2 for Trisquel / Gnu Linux trisquel 8.0|
|MacOS||Firefox||Firefox 73.0.1 for macOS version 10.15|
|MacOS||Safari||Safari 13.0.2 for macOS 10.15|
|MacOS||Chrome||Google Chrome 80.0 for macOS 10.15|
Vision for the project:
The overall vision for the project is to implement a tool that removes as many barriers as possible for organisations wanting to embed threat modelling into their development lifecycle. Barriers I have seen are:
- Lack of cross platform tooling: Tool needs to be x-platform
- Poor UX in existing tools, productivity is poor: Great UX is a must
- Steep learning curve for adopting teams: Tool to build in expert knowledge to help the team get started
- Models are ignored: Integration with other lifecycle tools is key
Initial high level plan:
Milestone 1: Alpha release - Basic threat modelling experience
- Architecture review of the existing prototype with refinement/change where required - complete: Confirmed JointJs works fine, Storage model changed and addition of Electon based desktop variant. Nools rule engine (no longer supported) replaced by json-rules-engine. Shifted from Grunt/Bower to NPM/Browserify
- Secure design review and implementation of findings
- Development of tests (unit and manual) - complete: Codecov report
- Draft end user documentation - complete: GitHub pages
- “Publicity drive” to sign up alpha/beta users and generate feedback Some progress on this. The desktop app has had 13k downloads - unclear how many people are actually using it. The GH repo for the desktop version has 79 stars. The web version gets about 94 unique visitors per day on average and the GH repo has 229 stars.
Milestone 2: Beta release - Threat/mitigation rule engine
- Refinement of UX based on feedback from the alpha release
- (Some) feature enhancements based on feedback from the alpha release Implemented some feature requests (e.g. snap-to-grid) and fixed issues reports (e.g. save bugs) by users
- Implementation of a rule engine for generation of threats/mitigations
- Updated tests and end-user documentation
Milestone 3: Release 1
- Key refinements, bug fixes and new features based on feedback from the beta release
- Complete end user documentation
- Penetration test
Milestone 4 - Dev lifecycle integration
- Detailed scope to be defined, but in general the vision is to support hooks into issue tracking and requirements management tool so that threats/mitigations can be tracked through to implementation and test
This is hard to estimate as it could change a lot if there were other developers involved. Based on my current velocity with just me, I would say release 1 could be complete in 1 year (optimistically).
Following an architecture review the following key changes were made:
- A new Electron based, installable desktop variant was introduced using the local file system for model storage
- The web variant was changed to use GitHub for model storage - other source control systems will follow (e.g. BitBucket)
- Seperation of common code into a new NPM package, shared between the web and desktop variants
- The Nools rule engine will be replaced since it is no longer maintained
- Getting enough usage of the alpha and beta to get the UX and rule engine right
- Finding a sustainable way to host it, especially to support deeper GitHub/BitBucket/Etc. integration
Minimum Viable Product
- Application source code for a threat modeling tool
- End user documentation for the tool
- An online hosted version of the tool
- An installable, cross-platform desktop version of the tool
|v1.2||14 April 2020||Web app
|description for diagram elements
label applied to boundaries
save button always enabled
zoom functionality disabled
hot key copy and paste for diagram elements
|v1.1||15 Mar 2020||Web app||Duplicate element/diagram feature|
|v1.1||10 Mar 2020||Desktop||Bug fix for blank screen on new model,
and duplicate element/diagram feature
|v1.0||22 Feb 2020||Desktop||First full release for Windows, MacOS and Linux|
|v0.1.27-alpha||28 Jul 2019||Desktop||Windows only|
|v0.1.26||16 May 2017||Desktop||MacOS and Windows only|
|0.3.0||14 Mar 2017||Web app|
|v0.1.1-alpha||14 Mar 2016||Web app|