attack-surface.md

Attack Surface Analysis for dotnet/efcore

Attack Surface: SQL Injection

• Description: Exploiting vulnerabilities by injecting malicious SQL code into database queries, leading to unauthorized database access and manipulation.
• EF Core Contribution: EF Core, while promoting parameterized queries, allows developers to use raw SQL queries or dynamic LINQ construction which, if not handled carefully, can introduce SQL injection vulnerabilities. Specifically:
  • FromSqlRaw, ExecuteSqlRaw, and FromSqlInterpolated when used with unsanitized user input.
  • Dynamic LINQ queries built from user input without proper validation.
• Example:

  // Vulnerable code using string interpolation in FromSqlRaw
  string userInput = GetUserInput(); // Assume this gets unsanitized input like \'; DROP TABLE Users; --\'
  var users = context.Users.FromSqlRaw($"SELECT * FROM Users WHERE Username = '{userInput}'").ToList();

• Impact:
  • Unauthorized data access (reading sensitive data).
  • Data modification (updating or deleting data).
  • Data breach (exfiltration of data).
  • Potential command execution on the database server in severe cases.
• Risk Severity: Critical
• Mitigation Strategies:
  • Strictly use parameterized queries: Favor FromSqlInterpolated or ExecuteSqlInterpolated for raw SQL queries, which inherently handle parameterization.
  • Completely avoid string concatenation and interpolation of user input directly into SQL queries.
  • Prioritize using LINQ and EF Core's query building features to abstract away direct SQL construction and benefit from built-in parameterization.
  • Implement server-side input validation and sanitization even when using parameterized queries as a defense-in-depth measure.
  • Conduct regular code reviews specifically looking for potential SQL injection points, especially in areas dealing with user input and database interactions.

Attack Surface: Database Migration Misconfigurations

• Description: Insecure configuration or execution of EF Core database migrations, potentially leading to database schema manipulation, data corruption, or backdoor creation.
• EF Core Contribution: EF Core's migration feature automates database schema updates. Misconfigurations in how migrations are managed and applied can create security risks. Specifically:
  • Automated migration application in production without review or control.
  • Migrations containing insecure or malicious SQL scripts.
  • Overly permissive database credentials used for migration execution.
• Example:
  • Setting up an automated deployment pipeline that automatically applies EF Core migrations to the production database without manual review or testing in a staging environment. This could allow a compromised migration to be deployed directly to production.
• Impact:
  • Database schema manipulation (unauthorized changes to database structure).
  • Data corruption (data loss or integrity issues due to schema changes).
  • Potential backdoor creation (introduction of malicious stored procedures or triggers via migrations).
  • Denial of Service (disrupting database operations through schema changes).
• Risk Severity: High
• Mitigation Strategies:
  • Implement a secure and controlled migration process:
    • Mandatory review and approval of migrations before application to production environments.
    • Utilize separate environments (development, staging, production) and thoroughly test migrations in staging before production deployment.
    • Avoid automatic migration application in production. Implement manual triggers or controlled deployment pipelines for migrations.
  • Secure migration scripts:
    • Rigorous code review of migration scripts to identify and eliminate any potential security vulnerabilities, including SQL injection risks within migrations themselves.
    • Use parameterized SQL within migrations where dynamic values are needed.
    • Adhere to secure coding practices when developing migration logic.
  • Employ least privilege database credentials for migrations: Grant migration accounts only the minimum necessary permissions to alter the database schema, avoiding full administrative privileges.
  • Implement migration version control and rollback mechanisms to easily revert unintended or malicious migrations.
  • Maintain audit logs of all migration executions for traceability and security monitoring.

Attack Surface: Connection String Exposure

• Description: Insecure storage and management of database connection strings, which contain sensitive credentials required to access the database.
• EF Core Contribution: EF Core applications rely on connection strings to establish database connections. Insecure handling of these strings directly exposes the application to database compromise.
• Example:
  • Hardcoding connection strings directly within the application's source code, making them easily accessible in version control or compiled binaries.
  • Storing connection strings in plain text configuration files deployed with the application, vulnerable to access via web server vulnerabilities or misconfigurations.
• Impact:
  • Full database compromise.
  • Data breach (unauthorized access to all data within the database).
  • Data manipulation (malicious modification or deletion of data).
  • Denial of Service (disruption of database availability).
• Risk Severity: Critical
• Mitigation Strategies:
  • Absolutely avoid hardcoding connection strings in source code.
  • Utilize secure storage mechanisms for connection strings, such as environment variables or dedicated secrets management solutions (e.g., Azure Key Vault, HashiCorp Vault, AWS Secrets Manager).
  • Encrypt connection strings in configuration files if local storage is unavoidable.
  • Restrict access to configuration files and secrets management systems using robust access control mechanisms and permissions.
  • Prevent committing connection strings to version control systems. Employ environment-specific configuration and secure deployment pipelines.