mitigations.md

Mitigation Strategies Analysis for ryanb/cancan

Mitigation Strategy: Rigorous Review and Testing of Ability Definitions

• Mitigation Strategy: Rigorous Review and Testing of Ability Definitions
• Description:
  1. Code Review of ability.rb: Conduct mandatory code reviews specifically for every change to the ability.rb file (or equivalent where CanCan abilities are defined). A second developer should meticulously examine the CanCan ability definitions, focusing on logic, conditions, and potential unintended consequences of these rules within the CanCan context.
  2. Unit Tests for CanCan Abilities: For each defined CanCan ability (e.g., can :read, Article), write dedicated unit tests. These tests should:
     • Instantiate a User object with different roles.
     • Instantiate the Ability class from CanCan with the test user.
     • Use ability.can? and ability.cannot? (CanCan methods) assertions to verify expected authorization outcomes for various actions and resources as defined in ability.rb. Test both positive and negative cases based on CanCan rules.
  3. Integration Tests Focusing on CanCan Authorization: Create integration tests that specifically simulate user interactions and verify CanCan's authorization enforcement within the application. These tests should:
     • Log in users with different roles.
     • Attempt to access protected resources or perform actions that are governed by CanCan abilities through the application's UI or API.
     • Assert that CanCan correctly authorizes or denies access based on the defined abilities in ability.rb.
  4. Automated Testing of CanCan Abilities: Integrate unit and integration tests specifically for CanCan ability definitions into the CI/CD pipeline to ensure that these definitions are automatically tested with every code change.
  5. Regular Audits of CanCan Ability Logic: Schedule periodic audits (e.g., quarterly) specifically of the ability.rb file by security-focused developers or external security consultants to identify potential weaknesses or inconsistencies in the CanCan authorization logic.
• Threats Mitigated:
  • Authorization Bypass (High Severity): Incorrectly defined CanCan abilities can lead to users gaining access to resources or actions they should not be permitted to access, directly due to flaws in CanCan configuration.
  • Privilege Escalation (High Severity): Flaws in CanCan ability logic might allow users to elevate their privileges beyond their intended roles, stemming from misconfigured CanCan rules.
  • Data Breach (High Severity): Unauthorized access due to flawed CanCan abilities can result in data breaches and exposure of sensitive information, directly caused by CanCan misconfiguration.
  • Business Logic Errors (Medium Severity): Incorrect CanCan authorization can disrupt intended workflows and business processes due to misapplied CanCan rules.
• Impact:
  • Authorization Bypass: High Reduction
  • Privilege Escalation: High Reduction
  • Data Breach: High Reduction
  • Business Logic Errors: Medium Reduction
• Currently Implemented:
  • Code reviews are partially implemented for all code changes, but specific focus on ability.rb and CanCan logic is inconsistent.
  • Unit tests exist for some core functionalities, but dedicated unit tests specifically for CanCan abilities are missing.
  • Integration tests cover basic user flows, but specific authorization scenarios related to CanCan are not comprehensively tested.
  • Automated testing is in place for core functionalities, but not specifically for CanCan ability definitions.
  • Regular audits of CanCan ability logic are not currently scheduled.
• Missing Implementation:
  • Mandatory and focused code reviews for ability.rb changes, specifically reviewing CanCan logic.
  • Dedicated unit tests for all CanCan ability definitions in ability.rb.
  • Comprehensive integration tests covering various authorization scenarios specifically testing CanCan enforcement.
  • Integration of CanCan ability tests into the automated CI/CD pipeline.
  • Scheduled regular security audits specifically of CanCan ability definitions in ability.rb.

Mitigation Strategy: Enforce CanCan Authorization Consistently Across Application Layers

• Mitigation Strategy: Enforce CanCan Authorization Consistently Across Application Layers
• Description:
  1. Controller Authorization using CanCan: Ensure that every controller action requiring authorization uses CanCan's authorize! or load_and_authorize_resource. Avoid relying solely on view-level checks, ensuring CanCan is the primary authorization mechanism.
  2. Service Layer Authorization with CanCan: If using a service layer, implement authorization checks within service objects using CanCan before performing any sensitive operations. Pass the current user to service methods and use CanCan::Ability#authorize! within the service to leverage CanCan's authorization engine.
  3. Background Job Authorization with CanCan: When background jobs perform actions requiring authorization, ensure CanCan is used to authorize these operations within the job's perform method. Retrieve the relevant user context and use CanCan::Ability#authorize! to apply CanCan's rules.
  4. API Endpoint Authorization with CanCan: For all API endpoints, implement authorization checks using CanCan before processing requests. This is crucial to protect API access from unauthorized clients or users using CanCan's framework.
  5. Centralized CanCan Authorization Logic: Avoid scattering authorization logic outside of CanCan's framework. Centralize it within controllers, services, and background jobs using CanCan's methods and ability.rb definitions.
• Threats Mitigated:
  • Authorization Bypass (High Severity): Inconsistent enforcement of CanCan can lead to bypassing controller-level checks through direct service calls, background jobs, or API access, if CanCan is not consistently applied.
  • Privilege Escalation (Medium Severity): If CanCan authorization is missed in certain layers, users might be able to perform actions they are not supposed to, due to gaps in CanCan enforcement.
  • Data Manipulation (High Severity): Bypassing CanCan authorization in background jobs or services could lead to unauthorized data modification or deletion, if CanCan is not applied in these contexts.
  • API Abuse (High Severity): Lack of API endpoint authorization using CanCan can expose sensitive data and functionalities to unauthorized external access, if CanCan is not used to protect APIs.
• Impact:
  • Authorization Bypass: High Reduction
  • Privilege Escalation: Medium Reduction
  • Data Manipulation: High Reduction
  • API Abuse: High Reduction
• Currently Implemented:
  • Controller authorization is generally implemented using load_and_authorize_resource in most controllers, leveraging CanCan.
  • Service layer authorization using CanCan is partially implemented in some services, but not consistently across all services.
  • Background job authorization using CanCan is not currently implemented.
  • API endpoint authorization using CanCan is implemented for some API endpoints, but not comprehensively.
• Missing Implementation:
  • Systematic review and implementation of CanCan authorization in all service layer methods.
  • Implementation of CanCan authorization checks in all background jobs that perform sensitive actions.
  • Comprehensive implementation of CanCan authorization for all API endpoints.
  • Establish guidelines and code review processes to ensure consistent CanCan authorization enforcement across all layers.

Mitigation Strategy: Careful Use of cannot Definitions in CanCan

• Mitigation Strategy: Careful Use of cannot Definitions in CanCan
• Description:
  1. Prioritize can in CanCan: When defining abilities in ability.rb, primarily use CanCan's can to explicitly grant permissions. Define the positive permissions first using can.
  2. Use cannot Sparingly in CanCan: Reserve CanCan's cannot for specific situations where you need to subtract permissions from a broader can rule within CanCan's ability definitions. Avoid using cannot as the primary way to define permissions in CanCan.
  3. Clear Documentation for cannot in CanCan: If cannot is used in ability.rb, thoroughly document the reason for its use and the specific permissions it revokes within the CanCan context. Explain the context and why a cannot rule is necessary in CanCan.
  4. Thorough Testing of cannot Logic in CanCan: When using cannot in CanCan, create specific unit and integration tests to verify that it functions as intended and does not inadvertently block legitimate access or create bypasses within CanCan's authorization framework. Test both scenarios where access should be blocked by cannot and scenarios where access should still be allowed despite the broader can rule in CanCan.
  5. Regular Review of cannot Rules in CanCan: During audits of CanCan ability definitions in ability.rb, pay special attention to cannot rules. Ensure they are still necessary and that their logic is clear and correct within the CanCan context.
• Threats Mitigated:
  • Authorization Logic Errors (Medium Severity): Over-reliance on cannot in CanCan can lead to complex and confusing ability logic in ability.rb, increasing the risk of errors in CanCan authorization rules.
  • Unintended Access Denials (Medium Severity): Incorrectly placed or overly broad cannot rules in CanCan can inadvertently block legitimate user access due to misconfigured CanCan rules.
  • Maintenance Complexity (Medium Severity): Complex CanCan ability definitions with numerous cannot rules are harder to maintain and understand in ability.rb, increasing the likelihood of introducing errors during updates to CanCan rules.
• Impact:
  • Authorization Logic Errors: Medium Reduction
  • Unintended Access Denials: Medium Reduction
  • Maintenance Complexity: Medium Reduction
• Currently Implemented:
  • Developers are generally encouraged to use can primarily in CanCan, but there's no strict enforcement or guideline against overuse of cannot within CanCan.
  • Documentation for cannot rules in CanCan is inconsistent.
  • Testing of cannot rules in CanCan is not specifically emphasized or prioritized.
  • Review of cannot rules in CanCan is not part of regular audits.
• Missing Implementation:
  • Establish a guideline or best practice document emphasizing the prioritized use of can and limited use of cannot within CanCan ability definitions.
  • Mandate documentation for all cannot rules in CanCan's ability.rb.
  • Include specific test cases for cannot rules in CanCan in unit and integration tests.
  • Specifically review cannot rules during regular CanCan ability definition audits.

Mitigation Strategy: Secure Handling of Ability Conditions in CanCan

• Mitigation Strategy: Secure Handling of Ability Conditions in CanCan
• Description:
  1. Simplicity in CanCan Conditions: Strive for simple and straightforward conditions in CanCan ability definitions within ability.rb. Avoid overly complex logic within CanCan conditions. Break down complex conditions into simpler, more manageable parts if possible within CanCan.
  2. Input Sanitization in CanCan Conditions: If CanCan conditions rely on user input (e.g., parameters from requests) or data from external sources, rigorously sanitize and validate this input before using it in CanCan conditions to prevent injection attacks (e.g., SQL injection if CanCan conditions involve database queries).
  3. Database Query Optimization in CanCan Conditions: When CanCan conditions involve database queries (e.g., checking ownership of a resource), optimize these queries for performance. Avoid inefficient queries in CanCan conditions that could lead to performance bottlenecks or denial-of-service vulnerabilities. Use indexes and efficient query patterns within CanCan conditions.
  4. Avoid Business Logic in CanCan Conditions: CanCan conditions should primarily focus on authorization checks, not complex business logic. Move complex business logic to service layers or model methods and call these from CanCan conditions if necessary, keeping the CanCan condition itself simple.
  5. Testing of CanCan Conditions: Thoroughly test CanCan ability definitions with conditions, especially those involving user input or database queries. Test various input values, including edge cases and potentially malicious inputs, to ensure CanCan conditions behave as expected and are secure within the CanCan framework.
• Threats Mitigated:
  • Injection Attacks (High Severity): Unsanitized input in CanCan conditions can lead to injection vulnerabilities (e.g., SQL injection) if CanCan conditions involve database queries.
  • Performance Issues/DoS (Medium Severity): Inefficient database queries in CanCan conditions can cause performance degradation and potentially lead to denial-of-service if many CanCan authorization checks are performed.
  • Authorization Logic Errors (Medium Severity): Complex or poorly written CanCan conditions can introduce errors in authorization logic, leading to unintended access or denial of access within CanCan's framework.
• Impact:
  • Injection Attacks: High Reduction
  • Performance Issues/DoS: Medium Reduction
  • Authorization Logic Errors: Medium Reduction
• Currently Implemented:
  • Developers are generally aware of input sanitization, but specific guidelines for CanCan conditions in ability definitions are lacking.
  • Database query optimization is considered in general development, but not specifically in the context of CanCan conditions.
  • Simplicity in CanCan conditions is encouraged, but not strictly enforced.
  • Testing of CanCan conditions is part of general testing, but not specifically focused on security aspects of CanCan conditions.
• Missing Implementation:
  • Develop specific guidelines for writing secure and efficient CanCan conditions in ability definitions, emphasizing input sanitization and query optimization within CanCan.
  • Include security-focused testing of CanCan conditions, specifically for injection vulnerabilities and performance related to CanCan.
  • Code review checklists should include a section on reviewing the security and efficiency of CanCan ability conditions.
  • Provide training to developers on secure coding practices specifically for CanCan conditions.

Mitigation Strategy: Stay Updated with CanCan Security Patches

• Mitigation Strategy: Stay Updated with CanCan Security Patches
• Description:
  1. Monitor CanCan Releases: Regularly monitor the CanCan project's GitHub repository, release notes, and security mailing lists (if any) for new releases and security advisories specifically for CanCan.
  2. Automated Dependency Checks for CanCan: Implement automated dependency scanning tools (e.g., Bundler Audit, Dependabot, Snyk) in your CI/CD pipeline. These tools will automatically check for known vulnerabilities specifically in CanCan.
  3. Prompt Upgrades of CanCan: When security vulnerabilities are announced or new versions with security patches are released for CanCan, prioritize upgrading CanCan to the latest stable version as quickly as possible.
  4. Testing After CanCan Upgrades: After upgrading CanCan, run your full suite of unit, integration, and regression tests to ensure that the upgrade did not introduce any regressions or break existing functionality, especially CanCan authorization logic.
  5. Security Awareness for CanCan Updates: Educate developers about the importance of keeping CanCan dependencies updated and the process for monitoring and responding to security advisories related to CanCan.
• Threats Mitigated:
  • Known Vulnerabilities in CanCan (High Severity): Outdated versions of CanCan may contain known security vulnerabilities that attackers can exploit, directly related to CanCan library itself.
  • Zero-Day Exploits (Medium Severity): While less direct, staying updated with CanCan reduces the window of opportunity for attackers to exploit newly discovered vulnerabilities in CanCan before patches are widely available.
• Impact:
  • Known Vulnerabilities in CanCan: High Reduction
  • Zero-Day Exploits: Medium Reduction
• Currently Implemented:
  • Dependency scanning using Bundler Audit is implemented in the CI/CD pipeline, which includes CanCan in dependency checks.
  • Developers are generally aware of the need to update dependencies, but the process for monitoring CanCan specifically is not formalized.
  • Upgrades are performed periodically, but not always immediately upon security releases for CanCan.
  • Testing after upgrades is performed, but not specifically focused on authorization changes after CanCan upgrades.
• Missing Implementation:
  • Formalize a process for monitoring CanCan releases and security advisories specifically.
  • Establish a policy for promptly upgrading CanCan upon security releases.
  • Include specific test cases focused on authorization after CanCan upgrades in the test suite.
  • Regularly review and improve the dependency update process and security awareness among developers regarding CanCan.