mitigations.md

Mitigation Strategies Analysis for emberjs/ember.js

Mitigation Strategy: Safe Handling of htmlSafe (Ember-Specific)

1. Mitigation Strategy: Safe Handling of htmlSafe (Ember-Specific)

• Description:

  1. Avoid Direct Use with User Input: Never directly pass user-supplied data or data derived from user input to Ember's htmlSafe function.
  2. Prefer Component Arguments: Pass data to components as arguments. Ember's templating engine automatically escapes these, preventing XSS.
  3. Sanitize Before htmlSafe (If Necessary): If htmlSafe is absolutely unavoidable, use a robust sanitization library like DOMPurify before calling htmlSafe.
     • Install DOMPurify: yarn add dompurify or npm install dompurify.
     • Import DOMPurify and htmlSafe:

       import DOMPurify from 'dompurify';
       import { htmlSafe } from '@ember/template';

     • Sanitize and then use htmlSafe:

       let sanitizedHTML = DOMPurify.sanitize(userInput);
       this.safeHTML = htmlSafe(sanitizedHTML);

  4. Custom Handlebars Helpers: For complex, controlled HTML generation, create custom Handlebars helpers. These helpers should encapsulate the sanitization logic, keeping templates clean and maintainable. This is an Ember-specific way to manage dynamic HTML.
  5. Code Review: Enforce code review that will check for htmlSafe usage.

• Threats Mitigated:

  • Cross-Site Scripting (XSS) via htmlSafe: (Severity: High) - Prevents attackers from injecting malicious scripts by misusing Ember's htmlSafe function.

• Impact:

  • XSS via htmlSafe: Risk reduction: High. Eliminates the primary Ember-specific XSS vector related to htmlSafe.

• Currently Implemented:

  • Partially. Developers are generally aware, but there's no strict enforcement or consistent use of DOMPurify. Custom helpers are used sometimes, but not systematically. Code review is not always catching htmlSafe issues.

• Missing Implementation:

  • Mandatory use of DOMPurify (or equivalent) before any use of htmlSafe with potentially unsafe data.
  • Consistent use of custom Ember Handlebars helpers for dynamic HTML generation.
  • Stricter code review to catch htmlSafe misuse.
  • Automated linting rules to flag potentially unsafe htmlSafe uses.

Mitigation Strategy: Prototype Pollution Prevention (Ember.Object Specific)

2. Mitigation Strategy: Prototype Pollution Prevention (Ember.Object Specific)

• Description:

  1. Upgrade Ember.js: Ensure the project is using Ember.js 3.27 or later (this provides some built-in protection, but the following steps are still crucial).
  2. Use Object.create(null): When creating new objects within Ember code that might be populated with untrusted data, use Object.create(null) instead of {}. This is particularly relevant when dealing with Ember's object model.
  3. Input Validation and Sanitization (for Ember.set): Before using Ember.set (or similar methods) to set properties on Ember objects, validate and sanitize both the keys and values. This is crucial when the data originates from outside the trusted Ember application context.
     • Key Validation: Ensure keys are strings and match expected property names. Reject unexpected keys.
     • Value Sanitization: Sanitize values based on their expected type.
  4. Deep Copy (with Ember Objects): If merging untrusted data into an existing Ember object, create a deep copy of the Ember object first (using Lodash's _.cloneDeep or a similar method that correctly handles Ember objects), then merge the sanitized data into the copy.
  5. Freeze Objects: After initializing Ember objects with trusted data, use Object.freeze() to make them immutable.
  6. Code Review: Enforce code review that will check for prototype pollution unsafe code.

• Threats Mitigated:

  • Prototype Pollution (targeting Ember.Object): (Severity: High) - Prevents attackers from modifying the behavior of Ember's built-in objects and potentially executing arbitrary code within the Ember application.

• Impact:

  • Prototype Pollution (Ember.Object): Risk reduction: High. Addresses a specific vulnerability pattern within Ember's object model.

• Currently Implemented:

  • Partially. The project is on Ember 4.x. Object.create(null) is not consistently used. Input validation for Ember.set is not comprehensive. Deep copying and Object.freeze() are rarely used with Ember objects. Code review is not always catching prototype pollution issues.

• Missing Implementation:

  • Consistent use of Object.create(null) for relevant Ember objects.
  • Comprehensive input validation and sanitization before using Ember.set with potentially untrusted data.
  • Strategic use of deep copying when merging untrusted data into existing Ember objects.
  • More frequent use of Object.freeze() on initialized Ember objects.
  • Stricter code review and potentially static analysis to find potential Ember-specific prototype pollution vulnerabilities.

Mitigation Strategy: Secure use of {{link-to}} and transitionTo (Ember Routing)

3. Mitigation Strategy: Secure use of {{link-to}} and transitionTo (Ember Routing)

• Description:

  1. Whitelist Allowed Routes (Ember Routes):
     • Create a JavaScript module (e.g., app/utils/route-whitelist.js) that exports an array or object containing the names of all allowed Ember routes.
     • In components or controllers where Ember's {{link-to}} helper or transitionTo method is used with dynamic route names, import the whitelist.
     • Before generating the link or transitioning, check if the target Ember route is in the whitelist. If not, prevent the action or redirect to a safe default Ember route.
  2. Validate Route Parameters (Ember Route Parameters):
     • If route parameters are derived from user input, define validation rules for each parameter (using ember-cp-validations or custom functions).
     • Validate the parameters before passing them to Ember's {{link-to}} or transitionTo.
     • If validation fails, prevent the link/transition and show an error.
  3. Avoid Dynamic Route Names from User Input (Ember Route Names):
     • Never directly construct Ember route names from user input strings.
     • If the destination Ember route depends on user input, use a lookup table or mapping function to determine the correct Ember route name based on validated input. Example:

       // Instead of: this.transitionToRoute(userInput);
       const routeMap = {
         'profile': 'user.profile',
         'settings': 'user.settings',
         // ...
       };
       const validatedInput = validateUserInput(userInput); // Returns a safe key
       const routeName = routeMap[validatedInput] || 'index'; // Default to 'index'
       this.transitionToRoute(routeName);

  4. Code Review: Enforce code review that will check for open redirect vulnerabilities.

• Threats Mitigated:

  • Open Redirect (via Ember Routing): (Severity: Medium) - Prevents attackers from redirecting users to malicious websites through manipulated Ember links or transitions.

• Impact:

  • Open Redirect (Ember Routing): Risk reduction: High. Addresses a specific vulnerability pattern within Ember's routing system.

• Currently Implemented:

  • Not implemented. Dynamic Ember route names and parameters are sometimes used without proper validation.

• Missing Implementation:

  • Implementation of an Ember route whitelist.
  • Validation of Ember route parameters.
  • Avoiding direct use of user input for Ember route names.
  • Code review process to identify and prevent open redirect vulnerabilities in Ember routing.