Mitigation Strategy: Minimize Deep Inheritance Hierarchies
Description:
1. Review the codebase and specifically identify class hierarchies established using inherits.
2. Analyze the depth of these hierarchies created with inherits. Aim to reduce nesting levels where possible, especially in new code.
3. When using inherits, consciously consider if deep hierarchies are necessary. Explore composition as an alternative to inherits-based inheritance for code reuse.
4. Refactor existing deep inheritance structures built with inherits by:
* Breaking down base classes involved in inherits into smaller, more focused components.
* Using composition to combine functionalities instead of relying on deep inherits chains.
5. Document the justification for any remaining deeper inheritance hierarchies that utilize inherits, particularly if exceeding 2-3 levels.
Threats Mitigated:
* Logic Errors due to Complexity (High Severity): Deep inheritance, facilitated by inherits, makes code harder to understand, increasing logic error risks and potential vulnerabilities.
* Maintenance Overhead (Medium Severity): Complex hierarchies using inherits are harder to maintain, delaying security updates and increasing vulnerability introduction during maintenance.
Impact:
* Logic Errors: Significantly reduces risk by simplifying code structure resulting from inherits usage, making flaw identification easier.
* Maintenance Overhead: Reduces maintenance burden of inherits-based hierarchies, enabling faster security response.
Currently Implemented: Partially implemented in newer modules. Older modules and plugins still use inherits to create deeper hierarchies.
Missing Implementation: Systematic review and refactoring of older modules and plugins to flatten inherits-based hierarchies. New code using inherits should strictly minimize depth.
Mitigation Strategy: Ensure Proper Encapsulation and Access Control in Parent and Child Classes (Using inherits)
Description:
1. Review all classes involved in inheritance relationships established by inherits.
2. Define clear access control for properties and methods in parent and child classes connected via inherits.
3. Minimize exposure of parent class internals to child classes when using inherits.
4. Utilize private/protected patterns (closures, naming conventions) to restrict access to members in inherits-based hierarchies, preventing unintended child class access.
5. Document access levels and inheritance contracts for classes using inherits to ensure clarity for developers.
Threats Mitigated:
* Information Exposure (Medium to High Severity): Unintentional exposure of parent class data to child classes in inherits hierarchies, leading to unauthorized access.
* Unintended Modification of State (Medium Severity): Child classes in inherits hierarchies inadvertently modifying parent state, causing security issues or inconsistencies.
* Bypassing Security Checks (Medium Severity): Child classes in inherits hierarchies bypassing parent class security checks due to loose access control.
Impact:
* Information Exposure: Significantly reduces risk by limiting access within inherits hierarchies, protecting sensitive data.
* Unintended Modification: Reduces risk of state corruption in inherits hierarchies and unexpected behavior.
* Bypassing Security Checks: Reduces risk of security mechanism circumvention within inherits inheritance.
Currently Implemented: Partially implemented. Naming conventions for "protected" members are used in inherits hierarchies, but consistent enforcement is needed.
Missing Implementation: Enforce encapsulation more strictly in code reviews and linting for code using inherits. Audit existing inherits classes for proper access control.
Mitigation Strategy: Thoroughly Test Inheritance Implementations (Using inherits), Especially Around Security-Sensitive Functionality
Description:
1. Identify all inheritance relationships created with inherits, especially in security-sensitive areas (authentication, authorization, validation).
2. Develop tests specifically for inheritance scenarios using inherits.
3. Focus testing on:
* Method overriding in inherits hierarchies: Ensure security requirements are maintained in overridden methods.
* Property access in inherits hierarchies: Verify secure and expected property manipulation.
* Polymorphism in inherits hierarchies: Test consistent security behavior across derived classes.
4. Integrate these tests into CI/CD for automated and regular testing of inherits-based inheritance.
Threats Mitigated:
* Logic Errors in Inheritance (High Severity): Undetected errors in inherits inheritance can lead to vulnerabilities like access bypasses and data corruption.
* Regression Bugs (Medium Severity): Changes in inherits hierarchies can break inheritance and introduce vulnerabilities if untested.
Impact:
* Logic Errors: Significantly reduces risk by early detection and fixing of errors in inherits inheritance.
* Regression Bugs: Reduces risk of new vulnerabilities from code changes in inherits hierarchies through consistent testing.
Currently Implemented: Basic unit tests exist, but inheritance-specific testing for inherits is not comprehensive, especially for security.
Missing Implementation: Develop comprehensive test suite for inherits inheritance, focusing on security. Integrate into CI/CD and ensure regular execution.
Mitigation Strategy: Regularly Review and Audit Code Utilizing inherits for Potential Logic Flaws
Description:
1. Schedule code reviews focused on code sections using inherits and inheritance patterns.
2. During reviews, focus on:
* Clarity and correctness of inherits inheritance relationships.
* Logic errors from method overriding or property access in inherits child classes.
* Adherence to encapsulation in inherits hierarchies.
* Security implications of inherits inheritance design.
3. Conduct security audits, focusing on inherits structures and potential vulnerabilities.
4. Use static analysis tools to detect issues in code using inherits (if applicable).
Threats Mitigated:
* Logic Errors (High Severity): Proactive identification of logic errors in inherits usage, reducing exploitable vulnerability risk.
* Design Flaws (Medium Severity): Identifying and addressing suboptimal inherits designs that could lead to security or maintenance issues.
Impact:
* Logic Errors: Reduces risk by proactively finding and fixing errors in inherits code.
* Design Flaws: Improves security and maintainability of codebase using inherits.
Currently Implemented: Code reviews for new features, but specific focus on inherits and security is inconsistent. Security audits may not deeply focus on inherits patterns.
Missing Implementation: Implement focused code reviews for inherits and security. Integrate security considerations into code review checklists for inherits code. Enhance audits to analyze inherits structures.
Mitigation Strategy: Consider Alternatives to Deep Inheritance (When Using inherits) if Security Concerns Arise from Complexity
Description:
1. When designing new features or refactoring, evaluate if deep inheritance via inherits is necessary.
2. If deep inherits inheritance leads to complexity or security concerns, consider alternatives.
3. Explore alternatives to inherits inheritance like:
* Composition: Favor composition over inherits for code reuse.
* Mixins (with caution): Use mixins instead of deep inherits hierarchies, but be mindful of complexity.
* Functional Programming: Consider functional approaches to reduce complexity associated with inherits object hierarchies.
4. Document rationale for design pattern choices, especially when avoiding inherits inheritance for security reasons.
Threats Mitigated:
* Logic Errors due to Complexity (High Severity): Reducing complexity by avoiding deep inherits inheritance mitigates logic error risks.
* Maintenance Overhead (Medium Severity): Simpler designs (avoiding deep inherits hierarchies) are easier to maintain, reducing vulnerability risks during maintenance.
Impact:
* Logic Errors: Significantly reduces risk by simplifying codebase and making it easier to understand code using inherits.
* Maintenance Overhead: Reduces maintenance burden of complex inherits hierarchies and allows faster security response.
Currently Implemented: Developers can choose patterns, but no explicit guideline to consider alternatives to deep inherits inheritance for security.
Missing Implementation: Incorporate a design step to evaluate alternatives to inherits inheritance, especially for complexity/security. Provide guidelines on composition, mixins, functional approaches as alternatives to inherits.