threat-modeling.md

Threat Model Analysis for go-kratos/kratos

Threat: Rogue Service Registration (Spoofing)

• Threat: Rogue Service Registration (Spoofing)

  • Description: An attacker registers a malicious service with the Kratos service discovery mechanism (e.g., Consul, etcd, or Kratos' built-in discovery). The attacker's service impersonates a legitimate service, intercepting requests intended for the real service. This could involve setting up a service with the same name and advertised endpoints.
  • Impact: The attacker can intercept sensitive data (credentials, PII, financial data), manipulate responses, redirect users to phishing sites, or cause a denial of service by dropping requests. Compromise of the entire system is possible if the attacker impersonates a critical service (e.g., authentication).
  • Kratos Component Affected: registry package (service discovery interface and implementations), specific discovery implementations (e.g., registry/consul, registry/etcd), and potentially any component relying on service discovery (e.g., transport/grpc and transport/http clients).
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Implement Mutual TLS (mTLS): Enforce mTLS between all services using Kratos' transport options. This ensures that only services with valid certificates can communicate.
    • Secure Service Discovery: Use strong authentication and authorization for the service discovery backend (e.g., Consul ACLs, etcd authentication). Restrict who can register services.
    • Service-to-Service Authorization: Implement policies (e.g., using OPA or Kratos' middleware) to control which services can communicate, even if a rogue service registers.
    • Auditing: Regularly audit service registrations and configurations in the discovery backend.

Threat: Configuration Tampering (Tampering)

• Threat: Configuration Tampering (Tampering)

  • Description: An attacker gains access to the configuration source used by Kratos (file, environment variables, remote config server) and modifies settings. They could change service endpoints to point to malicious servers, disable security features (like TLS or authentication), or inject malicious configuration values.
  • Impact: The attacker can redirect traffic, disable security controls, inject malicious code, or cause a denial of service. The severity depends on the modified configuration.
  • Kratos Component Affected: config package and its various source implementations (e.g., config/file, config/env, config/apollo), and any component using the configuration (virtually all components).
  • Risk Severity: High to Critical (depending on the configuration modified)
  • Mitigation Strategies:
    • Secure Configuration Source: Protect the configuration source with strong access controls, encryption at rest (if applicable), and audit logging.
    • Configuration Validation: Implement strict validation of configuration values within the Kratos application. Ensure values are within expected ranges and adhere to security policies. Use Kratos' config.Validator interface.
    • Secrets Management: Use a secrets management solution (e.g., HashiCorp Vault, AWS Secrets Manager) to store sensitive configuration values (API keys, passwords).
    • Version Control: Use a configuration source that supports versioning and rollback (e.g., Git, a dedicated configuration management system).

Threat: gRPC Message Interception/Modification (Tampering)

• Threat: gRPC Message Interception/Modification (Tampering)

  • Description: If TLS is disabled or misconfigured for gRPC communication, an attacker on the network can intercept and modify gRPC messages between services. This is a "man-in-the-middle" attack.
  • Impact: The attacker can read sensitive data, modify requests and responses, inject malicious data, or cause a denial of service.
  • Kratos Component Affected: transport/grpc (server and client).
  • Risk Severity: High (if TLS is not enforced)
  • Mitigation Strategies:
    • Enforce TLS: Always use TLS for gRPC communication. Configure strong cipher suites and ensure proper certificate validation in Kratos' transport/grpc options.
    • Certificate Pinning (Optional): For extra security, consider certificate pinning, although this can make certificate rotation more complex.

Threat: HTTP Message Interception/Modification (Tampering)

• Threat: HTTP Message Interception/Modification (Tampering)

  • Description: Similar to gRPC, if HTTPS is not enforced, an attacker can intercept and modify HTTP traffic between services or between clients and services.
  • Impact: Data breach, data manipulation, session hijacking, denial of service.
  • Kratos Component Affected: transport/http (server and client).
  • Risk Severity: High (if HTTPS is not enforced)
  • Mitigation Strategies:
    • Enforce HTTPS: Always use HTTPS for HTTP communication. Configure strong cipher suites and certificate validation.
    • HSTS: Use HTTP Strict Transport Security (HSTS) to prevent downgrade attacks.

Threat: Sensitive Information Disclosure in Logs/Errors (Information Disclosure)

• Threat: Sensitive Information Disclosure in Logs/Errors (Information Disclosure)

  • Description: Kratos logs sensitive data (API keys, passwords, PII) or returns detailed error messages to clients, revealing internal implementation details or sensitive information.
  • Impact: Exposure of sensitive data to unauthorized users or attackers, aiding in further attacks.
  • Kratos Component Affected: log package, error handling in all components (especially transport and any custom middleware).
  • Risk Severity: High
  • Mitigation Strategies:
    • Log Redaction: Redact or mask sensitive data in log messages. Use Kratos' logging middleware or custom logging functions to achieve this.
    • Generic Error Messages: Return generic error messages to clients, avoiding revealing internal details. Log detailed error information internally.
    • Review Error Handling: Carefully review error handling code to ensure it doesn't leak sensitive information.

Threat: Denial of Service via Resource Exhaustion (Denial of Service)

• Threat: Denial of Service via Resource Exhaustion (Denial of Service)

  • Description: An attacker floods a Kratos service with requests, consuming resources (CPU, memory, network connections) and making the service unavailable to legitimate users.
  • Impact: Service outage, disruption of business operations.
  • Kratos Component Affected: transport/grpc, transport/http (servers), and potentially any component handling requests.
  • Risk Severity: High
  • Mitigation Strategies:
    • Rate Limiting: Implement rate limiting using Kratos' middleware or an API gateway.
    • Connection Limits: Configure limits on the number of concurrent connections.
    • Timeouts: Set appropriate timeouts for requests to prevent long-lived connections from consuming resources.
    • Load Balancing: Use a load balancer to distribute traffic across multiple instances of the service.

Threat: Authorization Bypass (Elevation of Privilege)

• Threat: Authorization Bypass (Elevation of Privilege)

  • Description: An attacker exploits a vulnerability in Kratos' authorization middleware or its configuration to gain access to protected resources without proper authorization.
  • Impact: Unauthorized access to sensitive data or functionality.
  • Kratos Component Affected: Any middleware used for authorization (custom or third-party), and the configuration of that middleware.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Secure Middleware Configuration: Carefully review and configure authorization middleware.
    • Principle of Least Privilege: Grant only the minimum necessary permissions to users and services.
    • Regular Audits: Regularly audit authorization policies and configurations.
    • Penetration Testing: Conduct penetration testing to identify and address authorization vulnerabilities.

Threat: Dependency Vulnerabilities (Elevation of Privilege)

• Threat: Dependency Vulnerabilities (Elevation of Privilege)

  • Description: A vulnerability in a dependency used by Kratos (or a dependency of a dependency) is exploited by an attacker to gain elevated privileges or execute arbitrary code. This directly impacts Kratos because it uses the vulnerable dependency.
  • Impact: Code execution, system compromise.
  • Kratos Component Affected: Potentially any component, depending on the vulnerable dependency.
  • Risk Severity: High to Critical (depending on the vulnerability)
  • Mitigation Strategies:
    • Dependency Management: Use a dependency management tool (e.g., go mod) to track dependencies.
    • Vulnerability Scanning: Use a Software Composition Analysis (SCA) tool to identify known vulnerabilities in dependencies.
    • Regular Updates: Keep Kratos and all its dependencies updated to the latest versions.
    • Vulnerability Management Process: Establish a process for prioritizing and remediating identified vulnerabilities.