attack-surface.md

Attack Surface Analysis for thoughtbot/factory_bot

Attack Surface: Overly Permissive Object Creation

• Description: Factories create objects with attributes or permissions that exceed the minimum required, bypassing intended security controls.
• How factory_bot Contributes: factory_bot provides the mechanism to easily create these overly permissive objects, often through default attribute values or easily misused traits.
• Example: A User factory defaults to admin: true, or a Post factory bypasses content validation, allowing creation of posts with malicious scripts.

  # Vulnerable Factory
  FactoryBot.define do
    factory :user do
      admin { true } # Defaulting to admin is dangerous
      password { "password" } # Weak password
    end
  end

• Impact: Unauthorized access to sensitive data or functionality, privilege escalation, data corruption, XSS (if bypassing content validation).
• Risk Severity: Critical
• Mitigation Strategies:
  • Least Privilege Defaults: Factories should default to the least privileged state. Explicitly set attributes to restrictive values (e.g., admin: false).
  • Trait-Based Privileges: Use traits for elevated privileges (e.g., trait :admin do; admin true; end). Require explicit use of these traits.
  • Enforce Model Validations: Ensure factories do not bypass model validations. Use build or build_stubbed and manually validate if necessary.
  • Code Reviews: Mandatory code reviews for all factory definitions, focusing on defaults and attribute assignments.
  • Linting: Implement custom linters to flag potentially dangerous factory defaults.

Attack Surface: Unintended Data Relationships

• Description: Factories create associated objects in ways that bypass authorization checks or create unexpected data dependencies.
• How factory_bot Contributes: factory_bot's association features can be misused to automatically create associated objects without proper security considerations.
• Example: A Comment factory automatically creates an associated User with admin: true, or a Project factory creates associated Task objects that bypass project-level access controls.

  # Vulnerable Factory
  FactoryBot.define do
    factory :comment do
      association :user, factory: :admin_user # Automatically creates an admin user
      body { "Some comment" }
    end
  end

• Impact: Unauthorized access to data, data leakage, violation of data integrity constraints.
• Risk Severity: High
• Mitigation Strategies:
  • Explicit Associations: Avoid automatic creation of associated objects unless strictly necessary and thoroughly reviewed.
  • Controlled Association Factories: Use separate, well-defined factories for associated objects, ensuring those factories adhere to least privilege.
  • Review Association Logic: Carefully review how associations are handled within factories.

Attack Surface: Predictable Sequence Misuse

• Description: Using predictable sequences for sensitive fields, allowing attackers to guess valid values.
• How factory_bot Contributes: factory_bot's sequence feature can be misused to generate predictable values for fields that should be unpredictable.
• Example: Using a sequence for an API key, a password reset token, or a user ID (in some contexts).

  # Vulnerable Factory
  FactoryBot.define do
    factory :api_key do
      sequence(:token) { |n| "API-KEY-#{n}" } # Predictable token
    end
  end

• Impact: Unauthorized access, impersonation, data breaches.
• Risk Severity: High
• Mitigation Strategies:
  • Avoid Sequences for Sensitive Data: Use secure random number generators (e.g., SecureRandom.hex) for sensitive fields.
  • Complex Sequences (Non-Sensitive Data): If sequences must be used, use complex, non-linear progressions.
  • Audit Sequence Usage: Review all uses of sequence.

Attack Surface: Factory Code Exposure in Production

• Description: Factory definitions are accessible or executable in the production environment.
• How factory_bot Contributes: This is a configuration and deployment issue, but factory_bot is the tool that would be exploited if exposed.
• Example: An attacker discovers a route or endpoint that allows them to invoke factory methods, creating users or manipulating data.
• Impact: Complete system compromise, data breaches, data corruption, denial of service.
• Risk Severity: Critical
• Mitigation Strategies:
  • Strict Environment Separation: Ensure factory_bot is only loaded in test and development environments (Gemfile, Rails configuration).
  • Deployment Verification: Verify that factory files are not included in the production build.
  • Secure Test Endpoints: Secure any test-related endpoints, even in development.

Attack Surface: Seed Data Vulnerabilities

• Description: Factories used to generate seed data introduce vulnerabilities into the application.
• How factory_bot Contributes: factory_bot is used as the mechanism to create the potentially vulnerable seed data.
• Example: A factory creates a seed user with a weak password or an administrator account with default credentials.
• Impact: Compromised seed accounts, potential for privilege escalation or data breaches.
• Risk Severity: High
• Mitigation Strategies:
  • Review Seed Data Generation: Carefully review scripts using factories for seed data.
  • Production Security Standards: Apply the same security standards to seed data generation as to production code. Use strong, randomly generated passwords and avoid default credentials.
  • Avoid Seeding Sensitive Data: Do not seed production databases with sensitive data. If necessary, use placeholder data or anonymization techniques.