mitigations.md

Mitigation Strategies Analysis for bettererrors/better_errors

Mitigation Strategy: Disable better_errors in Production Environments via Environment Configuration

• Mitigation Strategy: Disable better_errors in Production Environments via Environment Configuration.

• Description:

  1. Open your Gemfile.
  2. Locate the better_errors gem entry.
  3. Ensure it is placed within the development and test groups. This restricts the gem's inclusion to only these environments.

     group :development, :test do
       gem 'better_errors'
       gem 'binding_of_caller'
     end

  4. Run bundle install to update your gem dependencies based on the modified Gemfile.
  5. Verify your deployment process ensures the RAILS_ENV environment variable is correctly set to production during production deployments. This is typically configured in your server environment or deployment scripts.
  6. Test in a staging environment that mirrors production to confirm better_errors is not active when RAILS_ENV=production.

• Threats Mitigated:

  • Information Disclosure (High Severity): better_errors exposes detailed error messages, stack traces, local variables, and potentially even session data directly to users. This can reveal sensitive application internals, database schema details, file paths, and configuration information. Attackers can use this information to understand application vulnerabilities and plan further attacks.
  • Code Execution Vulnerabilities (Medium Severity): While better_errors itself isn't directly a code execution vulnerability, the detailed information it provides can significantly aid attackers in identifying and exploiting other vulnerabilities that could lead to code execution. The binding_of_caller gem, a dependency, allows interactive debugging in the browser, which, if exposed in production, could be severely misused.

• Impact:

  • Information Disclosure: High Risk Reduction. Effectively eliminates the risk of direct information disclosure via better_errors in production if correctly implemented.
  • Code Execution Vulnerabilities: Medium Risk Reduction. Reduces the attacker's ability to easily gather information needed to exploit potential code execution vulnerabilities.

• Currently Implemented: Yes, partially.

  • Location: Gemfile is configured with better_errors within development and test groups.
  • Verification: Deployment process should set RAILS_ENV=production, but this needs explicit confirmation.

• Missing Implementation:

  • Explicit Verification of RAILS_ENV in Deployment: Need to add a step in the deployment checklist or automated scripts to explicitly verify that RAILS_ENV is correctly set to production on production servers.
  • Staging Environment Testing: Formalize testing in a staging environment that mirrors production to confirm better_errors is inactive in production mode.

Mitigation Strategy: Explicitly Disable better_errors in Production Configuration

• Mitigation Strategy: Explicitly Disable better_errors in Production Configuration.

• Description:

  1. Open your config/environments/production.rb file.
  2. Add the following line within the Rails.application.configure do block:

     config.middleware.delete BetterErrors::Middleware

  3. Deploy the updated configuration to your production environment.
  4. Restart your application servers to ensure the configuration changes are applied.

• Threats Mitigated:

  • Information Disclosure (High Severity): Provides a redundant layer of defense against accidental activation of better_errors in production, further reducing the risk of sensitive information exposure.
  • Configuration Errors (Low Severity): Mitigates risks associated with misconfiguration or unexpected behavior in environment loading that might inadvertently load development gems in production.

• Impact:

  • Information Disclosure: High Risk Reduction (Incremental). Adds an extra layer of security, making it even less likely for better_errors to be active in production due to configuration errors.
  • Configuration Errors: Low Risk Reduction. Reduces the risk of misconfiguration leading to unintended loading of development middleware.

• Currently Implemented: No.

  • Location: Not implemented in config/environments/production.rb.

• Missing Implementation:

  • Add the explicit middleware deletion to config/environments/production.rb.
  • **Include this configuration change in the next deployment cycle.

Mitigation Strategy: Remove better_errors and binding_of_caller Gems from Production Bundles

• Mitigation Strategy: Remove better_errors and binding_of_caller Gems from Production Bundles.

• Description:

  1. Modify your deployment process to use Bundler's --without flag during gem installation in production.
  2. Ensure your deployment scripts or commands include:

     bundle install --deployment --without development test

     This command instructs Bundler to install gems for the production environment only, excluding gems in the development and test groups.
  3. Verify in your production deployment that the better_errors and binding_of_caller gems are not present in the deployed application bundle (e.g., check Gemfile.lock in production).

• Threats Mitigated:

  • Accidental Activation (Medium Severity): Physically removes the gem code from the production environment, making it impossible for better_errors to be accidentally loaded or activated, even if there's a configuration error.
  • Supply Chain Security (Low Severity): Reduces the attack surface by removing unnecessary code from the production environment. While better_errors itself is unlikely to be a direct supply chain risk, minimizing dependencies in production is a good security practice.

• Impact:

  • Accidental Activation: High Risk Reduction. Eliminates the possibility of accidental activation by removing the code itself.
  • Supply Chain Security: Low Risk Reduction. Marginally improves supply chain security by reducing unnecessary dependencies.

• Currently Implemented: No.

  • Location: Deployment scripts likely use bundle install --deployment, but the --without development test flag is missing.

• Missing Implementation:

  • Update deployment scripts and documentation to include bundle install --deployment --without development test.
  • Test the updated deployment process in a staging environment to confirm gems are correctly excluded.