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Mitigation Strategies Analysis for varvet/pundit

Mitigation Strategy: Comprehensive Test Coverage for Policies

Description:

  1. Identify All Policies and Actions: List all Pundit policies and the actions (methods) within each policy that control access (e.g., show?, create?, update?, destroy?, policy_scope).
  2. Define Test Cases: For each action, define multiple test cases, including positive (allowed), negative (denied), edge cases, and different user roles/permissions. Test all branches of conditional logic within the Pundit policies.
  3. Write Tests: Use a testing framework (e.g., RSpec, Minitest) to write tests that:
    • Create mock users with specific roles and attributes.
    • Create mock resources (if necessary).
    • Call the Pundit policy action (e.g., policy.show?) with the mock user and resource.
    • Assert that the policy returns the expected boolean result (true or false).
    • Specifically test policy_scope to ensure it correctly filters records based on user permissions.
  4. Automate Tests: Integrate the tests into the CI/CD pipeline.
  5. Regularly Review and Update Tests: Update tests whenever policies change.

List of Threats Mitigated:

  • Incorrect Policy Logic (Critical): Flawed conditional statements within Pundit policies, incorrect use of Pundit helpers, misunderstandings of authorization requirements.
  • Data Leakage (High): Incorrect policy_scope logic in Pundit exposing unauthorized data.
  • Privilege Escalation (High): A user gaining access via a Pundit policy to actions or resources they shouldn't have.
  • Broken Access Control (High): General failure of the Pundit-based authorization system.

Impact:

  • Incorrect Policy Logic: Risk reduced significantly (70-90%).
  • Data Leakage: Risk reduced significantly (60-80%) if policy_scope is thoroughly tested.
  • Privilege Escalation: Risk reduced significantly (70-90%).
  • Broken Access Control: Risk reduced significantly (70-90%).

Currently Implemented:

  • Basic tests exist for ArticlePolicy covering create? and update?.
  • Tests are integrated into the CI/CD pipeline.

Missing Implementation:

  • No tests for CommentPolicy.
  • Incomplete coverage for ArticlePolicy (missing edge cases, roles, policy_scope).
  • Tests are not regularly reviewed/updated.

Mitigation Strategy: Code Reviews with Authorization (Pundit) Focus

Description:

  1. Mandatory Reviews: Require code reviews for all changes to Pundit policies.
  2. Pundit-Specific Checklist: Create a checklist for reviewing Pundit policies, including:
    • Does the Pundit policy logic exactly match the authorization requirements?
    • Are all conditions checked before granting access within the Pundit policy?
    • Is the policy_scope logic (if used) correct, efficient, and secure within the Pundit policy?
    • Are there any potential bypasses of the Pundit policy?
    • Are there sufficient Pundit-specific tests?
  3. Focus on Pundit Logic: Reviewers should focus on the logic of the Pundit policy methods, questioning every conditional.
  4. Document Review: Document findings and concerns.
  5. Approval: Require approval before merging.

List of Threats Mitigated:

  • Incorrect Policy Logic (Critical): Catches errors in Pundit policy logic.
  • Data Leakage (High): Identifies flaws in Pundit's policy_scope.
  • Privilege Escalation (High): Identifies ways a user could bypass Pundit policies.
  • Broken Access Control (High): Reduces risk of Pundit-based authorization failures.

Impact:

  • Incorrect Policy Logic: Risk reduced significantly (50-70%).
  • Data Leakage: Risk reduced moderately (40-60%).
  • Privilege Escalation: Risk reduced significantly (50-70%).
  • Broken Access Control: Risk reduced moderately (40-60%).

Currently Implemented:

  • General code reviews are required.

Missing Implementation:

  • No Pundit-specific checklist or focus.
  • Reviews often don't thoroughly examine Pundit policy logic.

Mitigation Strategy: Enforce authorize and policy_scope Calls (Pundit-Specific Enforcement)

Description:

  1. Identify Authorization Points: Determine where Pundit's authorize and policy_scope must be called (controllers, services, etc.).
  2. Centralized Pundit Helper (Recommended): Create a helper method (e.g., ensure_authorized_with_pundit) that wraps Pundit's authorize call. This enforces consistent Pundit usage. Do the same for policy_scope if appropriate.
  3. Static Analysis (Pundit-Aware): Use a linter or static analysis tool configured to detect missing calls to Pundit's authorize or policy_scope (or the custom helper) in the identified locations. This requires a tool that understands Pundit or can be configured with custom rules.
  4. CI/CD Integration: Integrate the static analysis into the CI/CD pipeline; violations fail the build.

List of Threats Mitigated:

  • Bypassing Pundit (High): Prevents accidentally omitting Pundit authorization checks.
  • Broken Access Control (High): Ensures consistent application of Pundit policies.

Impact:

  • Bypassing Pundit: Risk reduced significantly (80-95%).
  • Broken Access Control: Risk reduced significantly (70-90%).

Currently Implemented:

  • authorize is called in some controller actions.

Missing Implementation:

  • No centralized Pundit authorization helper.
  • No Pundit-aware static analysis tool.
  • No CI/CD integration for Pundit enforcement.

Mitigation Strategy: Avoid Direct params Access within Pundit Policies

Description:

  1. Identify Policy Inputs: Determine the data needed by each Pundit policy method.
  2. Pass Data as Arguments: Modify Pundit policy methods to accept data as explicit arguments, not by accessing params directly within the Pundit policy.
  3. Refactor Existing Policies: Review and refactor any Pundit policies that directly access params.

List of Threats Mitigated:

  • Injection Attacks (High): Prevents attackers from injecting data through params to manipulate Pundit's authorization logic. This is a direct threat to Pundit if params are used unsafely within a policy.
  • Broken Access Control (High): By controlling the data used in Pundit's authorization, this reduces the risk of incorrect access.

Impact:

  • Injection Attacks: Risk reduced significantly (80-95%) within the context of Pundit policies.
  • Broken Access Control: Risk reduced moderately (40-60%).

Currently Implemented:

  • None (for the sake of this example).

Missing Implementation:

  • All policies that need external data access params directly.
  • No refactoring has been done.