mitigations.md

Mitigation Strategies Analysis for dotnet/efcore

Mitigation Strategy: Always Use Parameterized Queries with Raw SQL in EF Core

• Description:

  1. Identify FromSqlRaw, ExecuteSqlRaw, SqlQuery Usage: Specifically within your EF Core codebase, locate all instances where you are using FromSqlRaw, ExecuteSqlRaw, or potentially older methods like SqlQuery. These methods in EF Core allow execution of raw SQL.
  2. Inspect for String Interpolation/Concatenation of User Input: Within these raw SQL strings used with EF Core, carefully examine if any user-provided data (originating from web requests, configuration, etc.) is being directly embedded into the SQL string via string interpolation or concatenation.
  3. Refactor to FromSqlInterpolated or Parameterized FromSqlRaw: Modify these vulnerable raw SQL queries within your EF Core context to utilize parameterized query mechanisms provided by EF Core.
     • Prefer using FromSqlInterpolated which provides a safer way to embed variables in SQL strings and automatically handles parameterization.
     • If FromSqlRaw is necessary, use parameter placeholders (like @p0, @p1 for SQL Server, or provider-specific syntax) and pass parameters as separate arguments to the method. EF Core will then handle proper parameterization.
  4. EF Core Query Testing: After refactoring, test the EF Core queries to ensure they function correctly with the parameterization changes. Verify that the application logic using these queries still works as intended.
  5. Establish EF Core Raw SQL Best Practices: For your development team, establish a clear best practice guideline that mandates the use of parameterized queries whenever raw SQL is employed within EF Core. Emphasize avoiding string interpolation/concatenation for user inputs in EF Core raw SQL contexts.

• List of Threats Mitigated:

  • SQL Injection via EF Core Raw SQL (High Severity): This directly mitigates SQL injection vulnerabilities that can arise specifically when using raw SQL features of EF Core improperly. Attackers could exploit these to execute arbitrary SQL commands through your EF Core data access layer, leading to data breaches, manipulation, or system compromise.

• Impact:

  • EF Core SQL Injection Risk Reduction: Significantly reduces the risk of SQL injection vulnerabilities specifically within the raw SQL usage areas of your EF Core application.

• Currently Implemented:

  • Potentially Partially Implemented in EF Core Context: Your project may be using LINQ extensively, which is inherently parameterized by EF Core. However, the use of raw SQL within EF Core (if any) might not consistently apply parameterization. Check areas using FromSqlRaw, ExecuteSqlRaw, SqlQuery.

• Missing Implementation:

  • Unparameterized Raw SQL in EF Core: Identify and refactor any instances of FromSqlRaw, ExecuteSqlRaw, or SqlQuery in your EF Core data access code that are still constructing SQL strings by directly embedding user inputs instead of using EF Core's parameterization features.

Mitigation Strategy: Disable Detailed EF Core Error Messages in Production

• Description:

  1. Locate EF Core DbContext Configuration: Find the section of your application's startup code (e.g., Startup.cs, Program.cs, or DbContext setup) where you configure your EF Core DbContext and specify the database provider (e.g., UseSqlServer, UseNpgsql).
  2. Configure Database Provider Options for Error Handling: Within the database provider configuration for your EF Core context, implement environment-based settings. Use IWebHostEnvironment (in ASP.NET Core) or similar mechanisms to detect if the application is running in a development or production environment.
  3. Disable Detailed Errors in Production EF Core Configuration: Specifically within the production environment configuration for your EF Core database provider, ensure that detailed error messages are disabled. For example, with SQL Server, this involves setting sqlServerOptions.EnableDetailedErrors(false). Consult the documentation for your specific database provider for the correct EF Core configuration option to control error detail level.
  4. Generic EF Core Exception Handling: Implement global exception handling within your application that intercepts database-related exceptions originating from EF Core operations. Ensure this handler returns generic, user-friendly error messages to clients and logs the detailed EF Core exception information securely server-side for debugging and diagnostics.
  5. Production Deployment Verification (EF Core Errors): After deploying to a production-like environment, specifically test scenarios that might trigger EF Core database errors. Verify that end-users receive generic error messages and that detailed EF Core error information is not exposed to them, but is logged server-side.

• List of Threats Mitigated:

  • Information Disclosure via EF Core Errors (Medium Severity): Mitigates information disclosure vulnerabilities arising from EF Core's detailed error messages in production. These messages can reveal sensitive database schema details, internal query structures, and potentially application paths, which could aid attackers in reconnaissance.

• Impact:

  • EF Core Error Information Leakage Prevention: Significantly reduces the risk of leaking sensitive information through EF Core error messages in production deployments.

• Currently Implemented:

  • Potentially Partially Implemented in EF Core Configuration: ASP.NET Core templates often have default configurations that reduce error detail in non-development environments. However, explicit configuration for EF Core error details and verification are needed. For non-ASP.NET Core applications, this might require manual setup in EF Core context configuration.

• Missing Implementation:

  • Explicit EF Core Error Detail Configuration Check: Verify the explicit configuration within your DbContext setup code to confirm that detailed error messages are definitively disabled for all database providers used by EF Core in production environments.
  • EF Core Exception Handling Middleware/Filters: Ensure robust global exception handling is in place to catch EF Core related exceptions and prevent raw exception details from reaching clients, even if database provider settings are missed.
  • Secure Logging of EF Core Errors: Verify that detailed EF Core error information is being logged securely on the server side when exceptions occur.

Mitigation Strategy: Use DTOs for EF Core Entity Updates from External Sources

• Description:

  1. Identify EF Core Update Operations from External Input: Pinpoint all areas in your application where EF Core entities are updated based on data originating from external sources (e.g., HTTP requests, message queues, external APIs).
  2. Define DTOs for EF Core Update Scenarios: For each identified update operation targeting EF Core entities, create dedicated Data Transfer Object (DTO) classes. These DTOs should specifically define only the properties that are intended to be updatable for that particular operation on the EF Core entity.
  3. Map External Data to DTOs Before EF Core Entity Update: When processing external input for updates, first map the incoming data to an instance of the appropriate DTO class. Use mapping libraries like AutoMapper or manual mapping.
  4. Fetch EF Core Entity for Update: Retrieve the target EF Core entity from the database using its identifier (e.g., FindAsync) before applying updates.
  5. Selective Property Update from DTO to EF Core Entity: Explicitly copy the validated properties from the DTO instance to the fetched EF Core entity. Only update the properties that are intended to be modified based on the DTO. Avoid directly binding the entire DTO to the entity or using methods that automatically update all entity properties based on DTO properties without explicit control.
  6. DbContext.SaveChanges() for EF Core Persistence: Use DbContext.SaveChanges() to persist the controlled updates to the database through EF Core.
  7. DTO Validation for EF Core Updates: Implement robust validation rules directly on the DTO properties. This validation should occur before mapping DTO properties to the EF Core entity, ensuring that only valid and intended data is used to update the entity via EF Core.

• List of Threats Mitigated:

  • Unintended Data Modification via EF Core Updates (Medium Severity): Reduces the risk of unintended data modification when updating EF Core entities based on external input. Using DTOs provides a controlled mechanism to prevent accidental or malicious updates to entity properties that should not be modified by external sources.

• Impact:

  • Controlled EF Core Entity Updates: Significantly increases control over which properties of EF Core entities are updated from external sources, reducing the risk of unintended modifications.

• Currently Implemented:

  • Potentially Partially Implemented in EF Core Update Flows: DTOs might be used for general data transfer in your application. However, their specific and consistent use for controlling updates to EF Core entities from external sources might be inconsistent.

• Missing Implementation:

  • EF Core Update Paths without DTOs: Identify update pathways in your application where external input is directly used to modify EF Core entities without the intermediary and control of DTOs.
  • Inconsistent DTO Usage for EF Core Updates: Ensure DTOs are consistently applied across all update operations targeting EF Core entities that originate from external sources.
  • Validation on DTOs for EF Core Updates: Implement and enforce validation rules on DTO properties to ensure data integrity and security before updating EF Core entities.

Mitigation Strategy: Optimize EF Core Queries for Performance and Resource Management

• Description:

  1. EF Core Query Logging and Database Profiling: Enable EF Core's query logging to capture the SQL queries generated by EF Core. Utilize database profiling tools specific to your database system (e.g., SQL Server Profiler, PostgreSQL pgAdmin query analyzer) to monitor the performance of EF Core generated queries in development and staging environments.
  2. Identify Slow EF Core Queries: Analyze EF Core query logs and profiling data to pinpoint slow-running or inefficient queries generated by EF Core. Focus on queries that are frequently executed or have a significant performance impact within your application's EF Core data access layer.
  3. Optimize EF Core LINQ Expressions: Review the identified slow EF Core queries and optimize the corresponding LINQ expressions. Consider EF Core specific optimization techniques:
     • Strategic Eager Loading (Include, ThenInclude in EF Core): Use eager loading in EF Core to reduce database round trips for related data when needed, but avoid over-fetching data that isn't required.
     • Projection with Select in EF Core: Employ Select in your EF Core LINQ queries to retrieve only the necessary columns from the database, minimizing data transfer overhead.
     • Efficient Filtering (Where in EF Core): Apply Where clauses as early as possible in your EF Core queries to reduce the dataset processed by the database.
     • Asynchronous Query Execution in EF Core (ToListAsync, FirstOrDefaultAsync): Use asynchronous methods provided by EF Core for database operations to prevent blocking threads, especially in web applications.
  4. Database Indexing for EF Core Queries: Ensure that appropriate indexes are created on database tables for columns frequently used in Where clauses, OrderBy clauses, and join conditions within your EF Core queries. Analyze query execution plans to identify missing indexes that could improve EF Core query performance.
  5. EF Core Caching Strategies: Implement caching mechanisms to reduce database load from frequently executed EF Core queries:
     • Leverage EF Core's First-Level Cache (Change Tracker): Understand and utilize EF Core's built-in change tracker, which acts as a first-level cache within the DbContext scope.
     • Consider Second-Level Caching for EF Core (External Libraries): Explore using third-party libraries that provide second-level caching for EF Core to cache query results across multiple requests and DbContext instances.
  6. Continuous EF Core Query Performance Monitoring: Establish ongoing performance monitoring of your application and database in production, specifically focusing on EF Core query performance. Use monitoring tools to track EF Core query execution times, database resource utilization related to EF Core operations, and identify performance regressions in EF Core data access.

• List of Threats Mitigated:

  • Denial of Service (DoS) via Inefficient EF Core Queries (Medium to High Severity): Mitigates potential Denial of Service (DoS) conditions that can arise from poorly performing EF Core queries. Inefficient queries can exhaust database resources or application server resources, leading to application unavailability.

• Impact:

  • Improved EF Core Application Resilience and Performance: Optimization of EF Core queries enhances application performance, reduces resource consumption, and makes the application more resilient to load and potential DoS attempts related to inefficient data access.

• Currently Implemented:

  • Potentially Partially Implemented in EF Core Data Access: Basic query optimization practices might be followed in your EF Core codebase. However, a systematic and continuous performance optimization strategy specifically focused on EF Core queries, including regular profiling and monitoring of EF Core operations, might be lacking. Indexing relevant to EF Core queries might be incomplete. Caching strategies for EF Core might be ad-hoc or missing.

• Missing Implementation:

  • Systematic EF Core Query Profiling and Optimization Process: Implement a defined process for regularly profiling EF Core queries, identifying performance bottlenecks in EF Core data access, and systematically optimizing slow EF Core queries.
  • Comprehensive Indexing Strategy for EF Core Queries: Review your database schema and EF Core query patterns to ensure all necessary indexes are in place to optimize the performance of your EF Core queries.
  • Layered Caching Strategy for EF Core Data: Develop and implement a layered caching strategy that includes appropriate caching mechanisms (second-level cache, distributed cache) specifically to improve the performance of frequently executed EF Core queries and reduce database load from EF Core operations.
  • Performance Monitoring and Alerting for EF Core Operations: Set up comprehensive performance monitoring in production environments, specifically tracking EF Core query performance metrics, and configure alerts for performance degradation in EF Core data access to proactively address issues.

Mitigation Strategy: Secure Review of EF Core Migration Scripts

• Description:

  1. Version Control for EF Core Migrations: Ensure all EF Core migration scripts generated by Add-Migration are under version control (e.g., Git) alongside your application code. This is fundamental for tracking changes and enabling reviews.
  2. Mandatory Pre-Deployment Review of EF Core Migrations: Establish a mandatory code review process specifically for all generated EF Core migration scripts before they are applied to any environment, especially production. This review should be a formal step in your deployment pipeline.
  3. Detailed Review of EF Core Migration Script Content: During the migration script review, carefully examine the SQL code within each script generated by EF Core.
     • Schema Change Verification (EF Core Migrations): Verify that the migration script only makes the intended database schema changes (table creation/modification, column changes, index creation, foreign key constraints, etc.) as dictated by your EF Core model changes. Ensure these changes align with the planned application updates and EF Core model modifications.
     • Data Modification Scrutiny in EF Core Migrations: If the EF Core migration includes data modifications (e.g., data seeding using context.AddRange, data transformations via raw SQL in migrations), rigorously scrutinize these operations. Ensure they are safe, correct, and do not introduce unintended data corruption, data loss, or security vulnerabilities.
     • Raw SQL Inspection in EF Core Migrations: Pay particular attention to any raw SQL code embedded within EF Core migration scripts (e.g., using Sql() method in migrations). If raw SQL is used, ensure it is parameterized if it involves any dynamic values and that it does not introduce SQL injection risks within the migration context.
     • Security Implication Assessment of EF Core Migrations: Consider if any schema changes or data modifications introduced by the EF Core migration could have security implications. For example, changes to database permissions, creation of new user roles, modifications to sensitive data handling within the database schema, or data seeding that introduces insecure default data.
  4. Automated Analysis of EF Core Migrations (Optional): Explore using static analysis tools or custom scripts to automatically scan EF Core migration scripts for potential issues. This could include syntax error checking, detection of potentially destructive schema changes, or basic security vulnerability scanning within the migration SQL.
  5. Non-Production Testing of EF Core Migrations: Always apply and thoroughly test EF Core migrations in development and staging environments before applying them to production. This allows for identifying and resolving any issues or unintended consequences of the EF Core schema changes in a safe, non-production setting.

• List of Threats Mitigated:

  • Data Integrity Issues via EF Core Migrations (Medium to High Severity): Reduces the risk of data integrity problems introduced by faulty or malicious EF Core migration scripts. Incorrect schema changes or data modifications in migrations can lead to data corruption, data loss, or application malfunctions directly related to database schema managed by EF Core.
  • Security Vulnerabilities via EF Core Migrations (Medium Severity): Mitigates the risk of inadvertently introducing security vulnerabilities through EF Core migration scripts. For instance, a migration could unintentionally alter database permissions managed by EF Core, create insecure default data within the EF Core managed schema, or introduce SQL injection vulnerabilities if raw SQL is misused in migrations.

• Impact:

  • Data Integrity and Security of EF Core Managed Database: Significantly reduces the risk of data integrity issues and security vulnerabilities being introduced into the database schema managed by EF Core through database migrations, by ensuring human review and pre-production testing of migration scripts.

• Currently Implemented:

  • Potentially Partially Implemented for EF Core Migrations: Version control for EF Core migrations is likely in place as it's a standard practice for code management. Testing migrations in non-production environments is also probably practiced to some degree. However, a formal, mandatory code review process specifically dedicated to EF Core migration scripts might be missing or inconsistently applied.

• Missing Implementation:

  • Formalized EF Core Migration Review Process: Implement a formal and mandatory code review process specifically for all EF Core migration scripts before deployment to any environment beyond development. This process should be documented and consistently enforced.
  • Automated EF Core Migration Analysis (Enhancement): Explore and potentially implement automated analysis tools or scripts to scan EF Core migration scripts for potential issues as an additional step in the review process, to supplement human review.
  • Documented EF Core Migration Procedures: Document clear, step-by-step procedures for creating, reviewing, testing, and deploying EF Core database migrations to ensure consistency, security, and adherence to best practices within your development team.