mitigations.md

Mitigation Strategies Analysis for go-kit/kit

Mitigation Strategy: Enforce HTTPS for all external go-kit endpoints.

• Description:

  1. Configure go-kit HTTP transport: When setting up your HTTP transport within your go-kit service (using httptransport package), ensure you are using http.ListenAndServeTLS instead of http.ListenAndServe.
  2. Provide TLS Certificates: Load TLS certificates and private keys using http.ListenAndServeTLS. These certificates should be valid for the domain or hostname where your go-kit service is exposed.
  3. Apply to go-kit HTTP Server: This configuration is applied directly to the net/http server instance that go-kit uses to serve its endpoints. Ensure all externally accessible go-kit services are configured this way.
  4. Consider httptransport.ServerOptions: Utilize httptransport.ServerOptions in your go-kit HTTP server setup to further customize TLS settings if needed, although basic TLS configuration is handled by http.ListenAndServeTLS.

• Threats Mitigated:

  • Man-in-the-Middle (MitM) Attacks (High Severity): Interception of communication between clients and go-kit services.
  • Data Eavesdropping (High Severity): Unauthorized access to data transmitted to and from go-kit services.

• Impact:

  • Man-in-the-Middle (MitM) Attacks: High risk reduction for external communication with go-kit services.
  • Data Eavesdropping: High risk reduction for data transmitted to and from external clients of go-kit services.

• Currently Implemented:

  • HTTPS is implemented for the public API gateway, which acts as a reverse proxy in front of go-kit services. TLS termination happens at the gateway level (Nginx).

• Missing Implementation:

  • Direct TLS termination within individual go-kit services is not implemented. Internal service-to-service communication via HTTP within the cluster is not encrypted at the go-kit transport level.

Mitigation Strategy: Secure gRPC connections with TLS in go-kit services.

• Description:

  1. Configure go-kit gRPC transport: When setting up your gRPC transport within your go-kit service (using grpctransport package), use grpc.NewServer with grpc.Creds option.
  2. Load TLS Credentials for gRPC: Use credentials.NewServerTLSFromFile or credentials.NewServerTLSFromCert to load server certificates and keys for gRPC.
  3. Configure grpctransport.ServerOptions: Utilize grpctransport.ServerOptions to pass the configured grpc.ServerOptions including the TLS credentials to the go-kit gRPC server.
  4. Client-side TLS Configuration: When creating gRPC clients in other go-kit services (using grpctransport.NewClient), use grpc.WithTransportCredentials with credentials.NewClientTLSFromFile or credentials.NewClientTLSFromCert to configure TLS for client connections.

• Threats Mitigated:

  • Man-in-the-Middle (MitM) Attacks on gRPC (High Severity): Interception of gRPC communication between go-kit services or between clients and go-kit gRPC services.
  • Data Eavesdropping on gRPC (High Severity): Unauthorized access to data transmitted via gRPC in go-kit applications.

• Impact:

  • Man-in-the-Middle (MitM) Attacks on gRPC: High risk reduction for gRPC communication within go-kit applications.
  • Data Eavesdropping on gRPC: High risk reduction for data transmitted via gRPC in go-kit applications.

• Currently Implemented:

  • gRPC is used for internal service-to-service communication in go-kit applications, but TLS is not currently enabled for these connections.

• Missing Implementation:

  • TLS encryption for internal gRPC communication within go-kit services is missing. TLS for external gRPC endpoints (if any) is also missing.

Mitigation Strategy: Implement Input Validation Middleware in go-kit.

• Description:

  1. Create go-kit Middleware Function: Develop a middleware function that conforms to the go-kit middleware signature (taking a endpoint.Endpoint and returning a endpoint.Endpoint).
  2. Implement Validation Logic in Middleware: Within the middleware function, implement input validation logic. This can involve:
     • Accessing request context (e.g., HTTP request via httptransport.RequestContext).
     • Extracting request parameters or body.
     • Using validation libraries (like go-playground/validator/v10) or custom validation code to check input data against defined rules.
  3. Return Error on Validation Failure: If validation fails, the middleware should return an error. In go-kit HTTP transport, this error will be translated into an HTTP error response by the transport layer.
  4. Chain Middleware to go-kit Endpoints: Apply this input validation middleware to specific go-kit endpoints using endpoint.Chain or by wrapping endpoints with the middleware during service definition.

• Threats Mitigated:

  • Injection Attacks (High Severity): SQL injection, command injection, XSS, etc., targeting go-kit endpoints.
  • Data Integrity Issues (Medium to High Severity): Processing invalid data within go-kit services.
  • Denial of Service (DoS) (Medium Severity): Exploiting vulnerabilities through malformed input to overload go-kit services.

• Impact:

  • Injection Attacks: High risk reduction for go-kit endpoints.
  • Data Integrity Issues: High risk reduction for data processed by go-kit services.
  • Denial of Service (DoS): Medium risk reduction for input-related DoS attacks on go-kit services.

• Currently Implemented:

  • Basic input validation exists in some endpoint handlers, but it's not consistently implemented as reusable go-kit middleware.

• Missing Implementation:

  • A dedicated, reusable input validation middleware component for go-kit is missing. Consistent application of input validation across all relevant go-kit endpoints via middleware is not implemented.

Mitigation Strategy: Apply Authorization Middleware in go-kit.

• Description:

  1. Create go-kit Authorization Middleware: Develop a middleware function that conforms to the go-kit middleware signature.
  2. Implement Authorization Logic in Middleware: Within the middleware, implement authorization logic. This typically involves:
     • Retrieving authentication information from the request context (e.g., JWT from headers, session cookies).
     • Verifying authentication (e.g., JWT signature verification, session validation).
     • Checking user roles or permissions against required roles/permissions for the endpoint.
  3. Return Unauthorized Error on Failure: If authorization fails, the middleware should return an error, typically an http.StatusUnauthorized or http.StatusForbidden error in HTTP transport.
  4. Chain Authorization Middleware: Apply this authorization middleware to go-kit endpoints that require access control using endpoint.Chain.

• Threats Mitigated:

  • Unauthorized Access (High Severity): Access to sensitive go-kit endpoints and functionalities by unauthorized users or services.
  • Privilege Escalation (Medium to High Severity): Unauthorized users gaining access to functionalities they should not have, potentially leading to privilege escalation.

• Impact:

  • Unauthorized Access: High risk reduction for protected go-kit endpoints.
  • Privilege Escalation: Medium to High risk reduction by enforcing access control at the go-kit endpoint level.

• Currently Implemented:

  • Authorization checks are implemented in some endpoint handlers, but not consistently as reusable go-kit middleware. Basic role-based access control is in place for some endpoints.

• Missing Implementation:

  • A dedicated, reusable authorization middleware component for go-kit is missing. Consistent application of authorization across all protected go-kit endpoints via middleware is not fully implemented.

Mitigation Strategy: Secure Custom go-kit Middleware Components.

• Description:

  1. Security Review of Custom Middleware Code: Thoroughly review the code of any custom go-kit middleware you develop for potential security vulnerabilities. Pay attention to:
     • Input handling and validation within the middleware itself.
     • Error handling and logging in middleware.
     • Potential for resource exhaustion or performance issues in middleware.
     • Dependencies used by the middleware and their security status.
  2. Unit and Integration Testing with Security Focus: Write unit and integration tests for custom middleware, specifically focusing on security aspects. Test for:
     • Proper handling of invalid or malicious input.
     • Correct authorization enforcement (if applicable).
     • Resistance to common middleware vulnerabilities (e.g., timing attacks, race conditions).
  3. Dependency Management for Middleware: Manage dependencies of custom middleware carefully. Keep dependencies updated and scan them for known vulnerabilities.

• Threats Mitigated:

  • Vulnerabilities Introduced by Custom Code (Variable Severity): Security flaws in custom go-kit middleware can introduce vulnerabilities that affect all endpoints using that middleware.
  • Bypass of Security Measures (Variable Severity): Poorly written middleware might inadvertently bypass other security measures or introduce new attack vectors.

• Impact:

  • Vulnerabilities Introduced by Custom Code: Variable risk reduction, depending on the severity of vulnerabilities in custom middleware and the effectiveness of security review and testing.
  • Bypass of Security Measures: Variable risk reduction, depending on the nature of the middleware and the security measures it might affect.

• Currently Implemented:

  • Custom middleware is used for logging and request tracing in go-kit applications. Basic code reviews are performed, but dedicated security reviews and security-focused testing of middleware are not consistently performed.

• Missing Implementation:

  • Formal security review process for custom go-kit middleware is missing. Security-focused unit and integration testing of middleware is not consistently implemented. Dependency scanning specifically targeting middleware dependencies is not in place.

Mitigation Strategy: Regularly Update go-kit and Middleware Dependencies.

• Description:

  1. Track go-kit Releases: Monitor releases and security advisories for go-kit/kit on GitHub and official channels.
  2. Track Middleware Dependency Releases: Identify dependencies used by your go-kit middleware components (both custom and third-party). Monitor releases and security advisories for these dependencies.
  3. Regular Update Cycle: Establish a regular cycle for updating go-kit and its dependencies. This should be part of your application maintenance process.
  4. Test After Updates: After updating go-kit or middleware dependencies, run thorough tests (unit, integration, and potentially regression tests) to ensure compatibility and that updates haven't introduced regressions or broken existing functionality.

• Threats Mitigated:

  • Exploitation of Known Vulnerabilities (High Severity): Using outdated versions of go-kit or its dependencies with known security vulnerabilities exposes your application to exploitation.

• Impact:

  • Exploitation of Known Vulnerabilities: High risk reduction by patching known vulnerabilities in go-kit and its dependencies.

• Currently Implemented:

  • go-kit and dependencies are generally updated periodically, but not on a strict, regularly scheduled basis. Dependency updates are often triggered by feature work or bug fixes rather than proactive security maintenance.

• Missing Implementation:

  • A formal, scheduled process for regularly updating go-kit and middleware dependencies is missing. Proactive monitoring of security advisories for go-kit and its dependencies is not consistently performed.

Mitigation Strategy: Implement Rate Limiting Middleware for go-kit Endpoints.

• Description:

  1. Choose Rate Limiting Algorithm/Library: Select a rate limiting algorithm (e.g., token bucket, leaky bucket, fixed window) and a suitable Go library for implementing rate limiting middleware (there are several available, or you can build custom middleware).
  2. Create go-kit Rate Limiting Middleware: Develop a middleware function that conforms to the go-kit middleware signature.
  3. Configure Rate Limits: Define appropriate rate limits for your go-kit endpoints based on expected traffic patterns and resource capacity. Configure these limits within your rate limiting middleware.
  4. Apply Rate Limiting Middleware: Apply the rate limiting middleware to go-kit endpoints that are susceptible to abuse or DoS attacks using endpoint.Chain.
  5. Handle Rate Limit Exceeded: When a request exceeds the rate limit, the middleware should return an appropriate HTTP error response (e.g., 429 Too Many Requests) to the client.

• Threats Mitigated:

  • Denial of Service (DoS) Attacks (Medium to High Severity): Preventing attackers from overwhelming go-kit services with excessive requests.
  • Brute-Force Attacks (Medium Severity): Slowing down brute-force attacks against authentication endpoints or other sensitive endpoints in go-kit services.
  • Resource Exhaustion (Medium Severity): Protecting go-kit services from resource exhaustion due to sudden spikes in traffic or malicious request floods.

• Impact:

  • Denial of Service (DoS) Attacks: Medium to High risk reduction, depending on the effectiveness of the rate limiting configuration and the nature of the DoS attack.
  • Brute-Force Attacks: Medium risk reduction by making brute-force attacks slower and less effective.
  • Resource Exhaustion: Medium risk reduction by controlling request rates and preventing resource overload.

• Currently Implemented:

  • Rate limiting is implemented at the API gateway level (Nginx) for public API endpoints.

• Missing Implementation:

  • Rate limiting middleware is not implemented directly within go-kit services. Internal endpoints and specific, resource-intensive endpoints within go-kit services are not protected by rate limiting at the application level.

Mitigation Strategy: Sanitize Logs Generated by go-kit Components and Middleware.

• Description:

  1. Identify Sensitive Data in go-kit Logging: Review logs generated by go-kit's built-in components (e.g., transport logs, middleware logs) and your custom middleware. Identify any instances where sensitive data might be logged.
  2. Implement Sanitization in Logging Middleware: If you are using custom logging middleware in go-kit, implement sanitization logic within this middleware.
  3. Sanitize Before Logging: Ensure that any sensitive data is sanitized before it is passed to the logging system. Use techniques like masking, redaction, or tokenization.
  4. Review go-kit Logging Configuration: Review your go-kit logging configuration to ensure that sensitive data is not inadvertently included in default log outputs.

• Threats Mitigated:

  • Information Disclosure via Logs (High to Medium Severity): Exposure of sensitive data through logs generated by go-kit components and middleware.
  • Compliance Violations (Varies Severity): Logging sensitive data might violate data privacy regulations.

• Impact:

  • Information Disclosure via Logs: High to Medium risk reduction for sensitive data logged by go-kit components and middleware.
  • Compliance Violations: Medium to High risk reduction in terms of logging-related compliance issues.

• Currently Implemented:

  • Basic log sanitization is implemented in some application code, but not specifically targeting logs generated by go-kit framework components or middleware.

• Missing Implementation:

  • Systematic log sanitization for logs originating from go-kit framework itself and custom middleware is missing. A dedicated logging middleware component for sanitization is not implemented.