mitigations.md

Mitigation Strategies Analysis for simplecov-ruby/simplecov

Mitigation Strategy: Proper Dependency Management (Bundler Groups)

Description:

1. Gemfile Review: Open the project's Gemfile.

2. Group Declaration: Ensure that the simplecov gem is included within a Bundler group block that is excluded from production deployments. This is typically the :test or :development group, or a custom group like :coverage. This is the direct interaction with simplecov.

   group :test, :development do
     gem 'simplecov'
     # Other test/development gems
   end

3. Deployment Command: When deploying to production, always use the bundle install command with the --without option to exclude the specified groups (e.g., bundle install --without test development). This ensures simplecov and its dependencies are not installed in the production environment.

4. Deployment Script/System Integration: The deployment script or system (Capistrano, Heroku, etc.) must be configured to use the correct bundle install command with the --without option. This is a crucial step to enforce the dependency exclusion.

5. Verification: After deployment, verify that simplecov is not present in the production environment. This can be done by checking the installed gems (e.g., bundle list) or by attempting to require 'simplecov' in a Ruby console (which should fail).

List of Threats Mitigated:

• Accidental Inclusion in Production Code: (Severity: Medium) - Prevents simplecov from being included in the production build. This avoids unnecessary code, potential (though unlikely) runtime conflicts, and a slightly increased attack surface.

Impact:

• Accidental Inclusion in Production Code: Eliminates the risk of simplecov itself being deployed.

Currently Implemented:

• simplecov is correctly placed within the :test group in the Gemfile.

Missing Implementation:

• Explicit verification step in the deployment process to confirm that simplecov is not present.
• Documentation/training for developers on using bundle install --without ....

Mitigation Strategy: Conditional SimpleCov Execution (Environment Variable Control)

Description:

1. Environment Variable: Introduce an environment variable (e.g., COVERAGE, ENABLE_COVERAGE) that controls whether SimpleCov is started.

2. Conditional SimpleCov.start: Modify your test setup (usually in spec_helper.rb or test_helper.rb) to only start SimpleCov if the environment variable is set to a specific value (e.g., "true", "1", "yes").

   # In spec_helper.rb or test_helper.rb
   if ENV['COVERAGE'] == 'true'
     require 'simplecov'
     SimpleCov.start 'rails' # Or your custom profile
   end

3. CI/CD Configuration: In your CI/CD pipeline, set the environment variable (e.g., COVERAGE=true) to enable coverage reporting only during CI builds.

4. Local Development (Optional): Developers can optionally set the environment variable locally to generate coverage reports during development, but the default should be off.

5. Documentation: Clearly document the use of the environment variable and the expected behavior.

List of Threats Mitigated:

• Accidental Inclusion in Production Code: (Severity: Medium) - Provides an additional layer of safety. Even if simplecov were accidentally included in the production bundle (which the previous mitigation should prevent), it wouldn't be active unless the environment variable was explicitly set. This is a defense-in-depth measure.
• Information Disclosure (Development/CI Environment): (Severity: Low) - Makes it slightly less likely that coverage reports are generated unintentionally in non-CI environments.

Impact:

• Accidental Inclusion in Production Code: Provides a significant reduction in risk as a secondary safeguard.
• Information Disclosure: Minor reduction in risk.

Currently Implemented:

• Not implemented.

Missing Implementation:

• Adding the conditional SimpleCov.start logic to the test setup.
• Configuring the CI/CD pipeline to set the COVERAGE environment variable.
• Documenting the use of the environment variable.

Mitigation Strategy: SimpleCov Configuration (Filtering and Grouping)

Description:

1. Configuration File: Create a .simplecov file in the project root (or use inline configuration within your test setup).
2. Filtering: Use SimpleCov's filtering capabilities to exclude specific files or directories from coverage analysis. This is particularly useful for:
   • Third-party libraries: Exclude code that you don't control and don't need to test.
   • Configuration files: Exclude files that don't contain executable code.
   • Test helpers: Exclude files that are part of the test suite itself.
   • Example:

     # .simplecov
     SimpleCov.start do
       add_filter '/spec/'
       add_filter '/config/'
       add_filter '/vendor/'
     end

3. Grouping: Use SimpleCov's grouping feature to organize coverage results into logical groups (e.g., by feature, module, or component). This makes it easier to analyze the coverage data and identify areas that need more testing. This doesn't directly mitigate security risks, but it improves the usefulness of the reports, making it more likely that developers will address coverage gaps.
   • Example:

     # .simplecov
     SimpleCov.start do
       add_group 'Models', 'app/models'
       add_group 'Controllers', 'app/controllers'
       add_group 'Services', 'app/services'
     end

4. Minimum Coverage: Set a minimum coverage percentage threshold. SimpleCov can be configured to fail the build if the coverage falls below this threshold. This encourages developers to write more tests and maintain a high level of code coverage. This indirectly improves security by reducing the likelihood of untested code paths.
   • Example:

     # .simplecov
     SimpleCov.start do
       minimum_coverage 90 # Fail if coverage is below 90%
     end

5. Coverage Profiles: Define different coverage profiles for different types of tests (e.g., unit tests, integration tests). This allows you to have different filtering and grouping rules for different parts of your test suite.
6. Review and Update: Regularly review and update the SimpleCov configuration to ensure it remains relevant and effective as the project evolves.

List of Threats Mitigated:

• Information Disclosure (Development/CI Environment): (Severity: Low) - By filtering out irrelevant files, you reduce the amount of information exposed in the coverage reports. This makes the reports less valuable to an attacker.
• Accidental Inclusion in Production Code: (Severity: Very Low) - While not a primary mitigation, a well-configured SimpleCov setup can make it slightly less likely that it will cause issues even if accidentally included (due to reduced processing).

Impact:

• Information Disclosure: Provides a small reduction in the amount of information disclosed.
• Accidental Inclusion in Production Code: Negligible impact.

Currently Implemented:

• Basic SimpleCov.start 'rails' is used, but no advanced configuration (filtering, grouping, minimum coverage) is implemented.

Missing Implementation:

• Creation of a .simplecov file (or inline configuration) with filtering, grouping, and minimum coverage settings.
• Regular review and updates to the SimpleCov configuration.