threat-modeling.md

Threat Model Analysis for apache/dubbo

Threat: Remote Code Execution via Deserialization

• Threat: Remote Code Execution via Deserialization
  • Description: An attacker crafts a malicious serialized object and sends it as part of a Dubbo request. The vulnerable Dubbo service deserializes this object, triggering the execution of arbitrary code on the server. The attacker uses tools like ysoserial to generate payloads. This leverages vulnerabilities in how Dubbo handles untrusted serialized data.
  • Impact: Complete system compromise. The attacker gains full control over the server, allowing them to steal data, install malware, disrupt services, or pivot to other systems.
  • Affected Dubbo Component: dubbo-remoting module (specifically, the serialization/deserialization logic). The Serialization interface and its implementations (e.g., Hessian2Serialization, KryoSerialization, FastJsonSerialization) are the primary targets.
  • Risk Severity: Critical.
  • Mitigation Strategies:
    • Whitelist-Based Deserialization: Implement strict whitelisting of allowed classes during deserialization. Configure Dubbo to only deserialize trusted classes. Use Dubbo's checkSerialization and related configuration options (e.g., dubbo.application.check=true and defining dubbo.security.serialize.allowlist or dubbo.security.serialize.blocklist). This is the most important mitigation.
    • Avoid Java Serialization: Do not use Java's built-in serialization mechanism, as it is inherently vulnerable.
    • Secure Serialization Protocols: Prefer secure serialization protocols like Hessian2 (with proper whitelisting) or Protobuf. Even with Hessian2, whitelisting is essential.
    • Regular Updates: Keep Dubbo and all its dependencies (including serialization libraries) up-to-date to patch known vulnerabilities. This is crucial, but whitelisting is the primary defense.
    • Input Validation: Implement robust input validation and sanitization, but this is a secondary defense and should not be relied upon as the primary mitigation for deserialization vulnerabilities.

Threat: Denial of Service (DoS) via Request Flooding

• Threat: Denial of Service (DoS) via Request Flooding
  • Description: An attacker sends a large number of requests to a Dubbo service, overwhelming its resources (CPU, memory, network bandwidth). They might use tools like hping3 or custom scripts to generate the flood. This exploits Dubbo's handling of incoming requests and thread pool management.
  • Impact: Service unavailability. Legitimate users are unable to access the service, leading to business disruption, financial loss, and reputational damage.
  • Affected Dubbo Component: dubbo-remoting module (network layer, thread pool management), dubbo-rpc module (service invocation handling). The ThreadPool configuration and related settings are relevant.
  • Risk Severity: High.
  • Mitigation Strategies:
    • Rate Limiting: Implement rate limiting at the Dubbo service level using Dubbo's tps (transactions per second) limiter or custom filters. Configure appropriate tps values for each service.
    • Connection Limiting: Limit the number of concurrent connections from a single client or IP address. This can be configured indirectly through thread pool settings.
    • Timeout Configuration: Set appropriate timeouts for Dubbo requests to prevent slow clients from consuming resources. Use the timeout attribute in the Dubbo configuration (both on the provider and consumer side).
    • Resource Allocation: Ensure the Dubbo service has sufficient resources (CPU, memory, network bandwidth) to handle expected traffic and potential spikes. This is an operational concern, but directly impacts Dubbo's ability to handle load.
    • Circuit Breaker: Use Dubbo's circuit breaker functionality to prevent cascading failures and protect downstream services. Configure the circuitBreaker strategy.

Threat: Unauthorized Service Invocation

• Threat: Unauthorized Service Invocation
  • Description: An attacker directly invokes a Dubbo service without proper authentication or authorization. They might use tools like telnet or custom scripts to bypass security controls, directly interacting with the Dubbo protocol.
  • Impact: Unauthorized access to data and functionality. The attacker could read, modify, or delete data, or perform unauthorized actions, leading to data breaches, data corruption, and business disruption.
  • Affected Dubbo Component: dubbo-rpc module (service invocation handling), dubbo-config (configuration of security settings). The accesslog, token, and custom filter mechanisms are relevant.
  • Risk Severity: High.
  • Mitigation Strategies:
    • Authentication: Implement strong authentication mechanisms for Dubbo services. Use token-based authentication (e.g., JWT), API keys, or integrate with an existing identity provider (e.g., OAuth 2.0, LDAP). Use Dubbo's token attribute or custom filters to enforce authentication.
    • Authorization: Implement fine-grained authorization policies to control which clients can access specific Dubbo services and methods. Use role-based access control (RBAC) or attribute-based access control (ABAC). This can be implemented using custom Dubbo filters.
    • Network Segmentation: Isolate Dubbo services on a separate network segment. While not a direct Dubbo mitigation, it significantly reduces the attack surface.

Threat: Exploitation of Dubbo Framework Vulnerability

• Threat: Exploitation of Dubbo Framework Vulnerability
  • Description: An attacker exploits a known or zero-day vulnerability in the Dubbo framework itself (e.g., a bug in the protocol implementation, network handling, or configuration parsing). This is a vulnerability within Dubbo's code.
  • Impact: Varies depending on the vulnerability, but could range from denial of service to remote code execution (making it potentially Critical).
  • Affected Dubbo Component: Potentially any Dubbo module, depending on the specific vulnerability.
  • Risk Severity: Varies (High to Critical), depending on the vulnerability.
  • Mitigation Strategies:
    • Regular Updates: Keep Dubbo updated to the latest stable version to patch known vulnerabilities. This is the primary mitigation for this threat.
    • Security Advisories: Monitor security advisories and mailing lists related to Dubbo (e.g., Apache Dubbo's security announcements).
    • Vulnerability Scanning: Regularly scan the application and its dependencies (including Dubbo) for known vulnerabilities.
    • Penetration Testing: Conduct regular penetration testing to identify and address potential vulnerabilities, including zero-days.