threat-modeling.md

Threat Model Analysis for micro/go-micro

Threat: Malicious Service Registration

• Description: An attacker registers a rogue service with the go-micro service registry. The attacker's service impersonates a legitimate service. Clients using go-micro's client.Client then unknowingly connect to the malicious service. The attacker could exploit a weakness in how go-micro interacts with the registry, or provide crafted metadata that bypasses checks.
• Impact: Data exfiltration, command injection, denial of service, man-in-the-middle attacks, complete system compromise.
• Affected Go-Micro Component: Registry interface and its implementations (how go-micro interacts with the registry). The client.Client is directly affected as it uses the registry to discover services.
• Risk Severity: Critical
• Mitigation Strategies:
  • Registry Interaction Security: Ensure go-micro's interaction with the registry uses secure protocols (TLS) and validates registry responses.
  • Service Identity Verification: Implement a mechanism within go-micro (e.g., using middleware or custom wrappers) to verify the identity of services beyond just their name retrieved from the registry. This could involve cryptographic signatures or tokens. The client.Client should perform this verification.
  • Input Validation (Registry Data): go-micro should rigorously sanitize and validate all service metadata received from the registry before using it.
  • Go-Micro Configuration: Review and harden go-micro's configuration related to registry interaction, ensuring secure defaults and disabling any insecure features.

Threat: Unauthorized Service Access (Bypassing Go-Micro Auth)

• Description: A malicious or compromised service calls another service using go-micro's client.Client without proper authorization. The attacker bypasses go-micro's intended access controls (if any are configured), potentially gaining access to sensitive data or functionality. This focuses on vulnerabilities within go-micro's handling of authentication and authorization.
• Impact: Data breaches, unauthorized actions, privilege escalation, potential for system compromise.
• Affected Go-Micro Component: client.Client (for making calls), server.Server (for handling calls), and any custom go-micro middleware or wrappers that implement authentication/authorization. The auth package, if used, is directly affected. Focus is on the correct usage and implementation of these components.
• Risk Severity: High
• Mitigation Strategies:
  • Proper auth Package Use: If using go-micro's auth package, ensure it's correctly configured and integrated into both the client and server.
  • Custom Middleware: If implementing custom authentication/authorization middleware, ensure it's robust, follows security best practices, and is thoroughly tested.
  • Context Propagation: Ensure that authentication and authorization information is properly propagated through the call chain using context.Context within go-micro.
  • Input Validation (within Go-Micro): Even with authentication, go-micro's service handlers should validate all input received from other services.
  • Go-Micro Configuration (Auth): Review and harden go-micro's configuration related to authentication and authorization.

Threat: Message Interception (Eavesdropping within Go-Micro Transport)

• Description: An attacker intercepts communication between services facilitated by go-micro. This focuses on vulnerabilities within go-micro's transport layer, such as a failure to properly enable or configure TLS, or a vulnerability in the TLS implementation used by go-micro.
• Impact: Loss of confidentiality, data breaches, potential for credential theft.
• Affected Go-Micro Component: transport.Transport interface and its implementations (e.g., http.Transport, grpc.Transport). The client.Client and server.Server are indirectly affected, specifically how they use the Transport.
• Risk Severity: High
• Mitigation Strategies:
  • Enforce TLS (Go-Micro Config): Ensure that go-micro is configured to require TLS for all inter-service communication. Do not allow unencrypted traffic.
  • Strong Cipher Suites (Go-Micro Config): Configure go-micro's transport.Transport to use strong cipher suites and protocols (e.g., TLS 1.3).
  • Certificate Validation (Go-Micro Implementation): Ensure that go-micro's client.Client properly validates server certificates, and server.Server validates client certificates (in the case of mTLS). This is a critical implementation detail within go-micro.
  • Go-Micro Transport Plugin Review: Carefully review the chosen transport.Transport implementation for any known security issues or configuration weaknesses.

Threat: Message Tampering (within Go-Micro Transport/Codec)

• Description: An attacker intercepts and modifies messages exchanged between services using go-micro. This focuses on vulnerabilities within go-micro's transport or codec layers, such as a failure to provide integrity protection or a vulnerability in the serialization/deserialization process.
• Impact: Data corruption, unauthorized actions, system compromise, incorrect application behavior.
• Affected Go-Micro Component: transport.Transport interface and its implementations. The codec.Codec interface is also directly relevant, as it handles message serialization/deserialization. The client.Client and server.Server are indirectly affected.
• Risk Severity: High
• Mitigation Strategies:
  • TLS (for Integrity - Go-Micro Config): As with eavesdropping, enforcing TLS via go-micro's configuration provides integrity protection.
  • Secure Codec Implementation: Ensure the codec.Codec implementation used by go-micro is secure and does not introduce vulnerabilities during serialization/deserialization. Avoid custom codecs unless thoroughly vetted.
  • Message Signing (within Go-Micro): Implement message signing using a cryptographic signature scheme within go-micro (e.g., using middleware). The sender signs the message, and the receiver verifies the signature.

Threat: Misconfigured Go-Micro Plugins

• Description: go-micro plugins (for service discovery, transport, codecs, etc.) are misconfigured, introducing vulnerabilities specific to how go-micro uses them. For example, a misconfigured transport plugin might disable TLS, or a misconfigured registry plugin might skip crucial validation steps. This focuses on the interaction between go-micro and its plugins.
• Impact: Varies widely, but can lead to any of the other high/critical threats.
• Affected Go-Micro Component: Any plugin (registry.Registry, transport.Transport, broker.Broker, codec.Codec, client.Client, server.Server, selector.Selector, etc.) – specifically, how go-micro uses and configures these plugins.
• Risk Severity: High to Critical (depending on the plugin and misconfiguration)
• Mitigation Strategies:
  • Documentation Review (Go-Micro Specifics): Thoroughly review go-micro's documentation for each plugin used, paying close attention to security-related configuration options.
  • Secure Defaults (Go-Micro): Ensure go-micro is configured to use secure defaults for all plugins whenever possible.
  • Configuration Validation (within Go-Micro): Implement checks within your go-micro application to validate plugin configurations at startup.
  • Go-Micro Plugin Selection: Choose well-maintained and reputable go-micro plugins.

Threat: Insecure Selector Strategy (within Go-Micro)

• Threat: Insecure Selector Strategy (within Go-Micro)

  • Description: An attacker manipulates the service selection process within go-micro to direct traffic to a malicious instance. This could be done by influencing the selection algorithm (e.g., if it's predictable or based on externally controllable factors) or by exploiting a vulnerability in go-micro's selector implementation.
  • Impact: Traffic redirection to a malicious service instance, leading to data breaches, command execution, or denial of service.
  • Affected Go-Micro Component: selector.Selector interface and its implementations (e.g., registry.Selector, cache.Selector, roundrobin.Selector, random.Selector). The client.Client uses the selector, so it's directly affected by how go-micro implements and uses the selector.
  • Risk Severity: High
  • Mitigation Strategies:
    • Robust Strategies (Go-Micro Config): Configure go-micro to use robust, well-vetted selection strategies like random.Selector or roundrobin.Selector. Avoid custom strategies unless thoroughly reviewed for security.
    • Avoid Predictability (Go-Micro Implementation): Ensure go-micro's selection process is not predictable or easily influenced by external factors.
    • Go-Micro Selector Plugin Review: Carefully review the chosen selector.Selector implementation for any known security issues.
    • Service Identity Verification (Combined with Selection): Combine go-micro's selection with strong service identity verification (e.g., mTLS) to ensure that even if the selector is compromised, the client still connects to a legitimate service.

Threat: Outdated go-micro Version

• Threat: Outdated go-micro Version

  • Description: Using an outdated version of the go-micro framework itself that contains known security vulnerabilities within the framework's code.
  • Impact: Exploitation of known vulnerabilities in go-micro, leading to system compromise, data breaches, or other attacks.
  • Affected Go-Micro Component: The entire go-micro framework.
  • Risk Severity: High
  • Mitigation Strategies:
    • Regular Updates: Regularly update go-micro to the latest stable version.
    • Dependency Management: Use Go modules to manage and update go-micro and its dependencies.
    • Vulnerability Scanning (Go-Micro Specific): Use a vulnerability scanner that specifically targets Go applications and can identify known vulnerabilities in go-micro.
    • Security Advisories: Monitor security advisories for go-micro.