mitigations.md

Mitigation Strategies Analysis for hyperium/hyper

Mitigation Strategy: Keep Hyper Updated

• Description:

  1. Monitor Hyperium releases: Regularly check the official hyper repository on GitHub for new releases, security advisories, and release notes. Subscribe to Hyperium's announcement channels if available.
  2. Test updates: Before deploying updates to production, thoroughly test new hyper versions in a staging environment to identify any compatibility issues or regressions with your application's code and other dependencies.
  3. Update Hyper dependency: Use cargo update hyper (or your project's dependency management tool) to update the hyper crate to the latest stable version in your Cargo.toml file.
  4. Rebuild and redeploy: Rebuild your application with the updated hyper version and deploy it to your production environment.
  5. Continuous monitoring: Continue to monitor for new hyper releases and repeat this update process regularly to benefit from the latest security patches and bug fixes within hyper itself.

• Threats Mitigated:

  • Exploitation of known vulnerabilities within hyper library code (High Severity): Outdated hyper versions may contain known security flaws in its core HTTP handling logic, parsing, or connection management that attackers can exploit.
  • Exposure to unpatched bugs in hyper (Severity varies): Bugs in older hyper versions, even if not explicitly security vulnerabilities, can lead to unexpected behavior or instability that could be indirectly exploited.

• Impact:

  • Significantly reduces the risk of direct exploitation of vulnerabilities present in the hyper library itself.
  • Reduces the risk of encountering and being affected by bugs within hyper's code.

• Currently Implemented:

  • Partially implemented. hyper is updated occasionally when new features are needed or major version changes are required, but not on a strict security-focused update schedule.

• Missing Implementation:

  • Regular, scheduled hyper updates: Implement a process for regularly checking for and applying hyper updates, prioritizing security releases.
  • Automated update checks: Consider using tools or scripts to automate checking for new hyper releases and notifying the development team.
  • Formal testing process for hyper updates: Establish a documented testing procedure specifically for verifying the stability and functionality of the application after updating hyper.

Mitigation Strategy: Strict HTTP Protocol Compliance and Validation Post-Hyper Parsing

• Description:

  1. Validate request components after hyper parsing: Even though hyper handles initial HTTP parsing, implement application-level validation on the parsed request components (headers, URI, method, body) after hyper has processed them.
  2. Header validation beyond hyper's checks: Implement application-specific validation rules for headers, especially those critical to your application logic. This goes beyond hyper's basic HTTP compliance and enforces application-level expectations. Sanitize or reject headers that don't conform to these rules.
  3. URI and method validation within application routes: Within your application's route handlers, validate the URI and HTTP method to ensure they match the expected patterns and are valid for the specific route. This adds a layer of security on top of hyper's routing capabilities.
  4. Body validation based on expected content type: After hyper has processed the request body, validate its content based on the Content-Type header and your application's expectations. This includes schema validation, data type checks, and sanitization to prevent injection attacks.
  5. Enforce request body size limits via Hyper configuration: Utilize hyper's server builder configuration options to directly set limits on the maximum allowed request body size. This leverages hyper's built-in capabilities to prevent DoS attacks at the HTTP layer.

• Threats Mitigated:

  • HTTP Request Smuggling due to interpretation differences after hyper parsing (Medium to High Severity): While hyper handles parsing, inconsistencies in how the application interprets the parsed request components could still lead to smuggling. Application-level validation reduces this risk.
  • Header Injection Attacks exploiting application logic after hyper processing (Medium Severity): Attackers might try to inject malicious content into headers that hyper parses correctly, but the application then mishandles. Validation after hyper helps prevent this.
  • Denial of Service (DoS) via large requests at the Hyper layer (Medium Severity): Configuring request body size limits in hyper directly prevents resource exhaustion by rejecting oversized requests before they reach application logic.

• Impact:

  • Reduces the risk of HTTP request smuggling arising from application-level interpretation of parsed requests.
  • Reduces the risk of header injection attacks that exploit vulnerabilities in application logic after hyper's parsing.
  • Directly mitigates DoS attacks caused by excessively large requests by leveraging hyper's built-in limits.

• Currently Implemented:

  • Partially implemented. Some input validation exists within specific route handlers, but it's not consistently applied across all parts of the application and doesn't fully leverage hyper's body size limit configuration.

• Missing Implementation:

  • Consistent validation middleware after hyper parsing: Develop middleware that operates after hyper's parsing to enforce consistent validation rules across the application.
  • Application-specific header validation rules: Define and implement detailed validation rules for headers relevant to application logic, going beyond basic HTTP compliance.
  • Globally configured request body size limits in Hyper: Ensure request body size limits are configured directly within hyper's server builder for consistent enforcement at the HTTP layer.

Mitigation Strategy: Secure TLS Configuration within Hyper

• Description:

  1. Choose secure TLS backend compatible with Hyper: Select a well-vetted and actively maintained TLS backend that is known to work securely and efficiently with hyper (e.g., tokio-rustls, tokio-native-tls).
  2. Configure TLS version enforcement in Hyper's TLS builder: When configuring HTTPS in hyper, explicitly set the minimum TLS version to 1.2 or 1.3 using the TLS backend's configuration options. Disable older, insecure TLS versions directly within hyper's TLS setup.
  3. Specify strong cipher suites in Hyper's TLS builder: Configure the TLS backend through hyper's TLS builder to use a restricted list of strong and secure cipher suites. Prioritize ciphers with forward secrecy and resistance to known attacks. Exclude weak or outdated ciphers directly in hyper's TLS configuration.
  4. Enable HSTS in Hyper application responses: Implement HSTS by setting the Strict-Transport-Security header in responses generated by your hyper application. This is done at the application level but is crucial for secure HTTPS usage with hyper.

• Threats Mitigated:

  • Man-in-the-Middle (MitM) attacks against HTTPS connections handled by hyper (High Severity): Secure TLS configuration within hyper is essential to prevent attackers from intercepting and decrypting HTTPS traffic.
  • Protocol Downgrade Attacks targeting hyper's HTTPS (Medium to High Severity): Enforcing strong TLS versions in hyper prevents attackers from forcing connections down to weaker, vulnerable TLS protocols.
  • Cipher Suite Weakness Exploitation in hyper's HTTPS (Medium Severity): Using strong cipher suites configured within hyper prevents attackers from exploiting weaknesses in outdated ciphers to compromise encrypted communication.

• Impact:

  • Significantly reduces the risk of MitM attacks, protocol downgrade attacks, and cipher suite exploitation for HTTPS connections managed by hyper.

• Currently Implemented:

  • Partially implemented. TLS is enabled using tokio-rustls with hyper. HSTS headers are set in responses. However, explicit TLS version enforcement and cipher suite hardening within hyper's TLS configuration are likely using defaults and haven't been explicitly secured.

• Missing Implementation:

  • Explicit TLS version configuration in Hyper: Configure the chosen TLS backend through hyper's TLS builder to enforce TLS 1.2 or 1.3 as the minimum version.
  • Cipher suite hardening in Hyper's TLS settings: Define a secure cipher suite list and configure hyper's TLS backend to use only these ciphers, ensuring strong encryption for HTTPS connections.
  • Regular audits of hyper's TLS configuration: Periodically review the TLS configuration within hyper to ensure it remains secure and aligned with current best practices for HTTPS.

Mitigation Strategy: Connection Management and Resource Limits within Hyper

• Description:

  1. Configure hyper's connection pool settings: Utilize hyper's Http builder to configure connection pool parameters like pool_max_idle_per_host, pool_idle_timeout, and max_concurrent_connections. Tune these settings based on server resources and expected load to optimize connection reuse and prevent resource exhaustion within hyper.
  2. Set timeouts in Hyper's server builder: Configure timeouts directly within hyper's server builder using methods like http2_keep_alive_timeout, http1_keep_alive_timeout, max_idle_connection_timeout, and request/response timeouts if available in the chosen hyper version. These timeouts are managed by hyper itself.
  3. Tune keep-alive settings in Hyper: Adjust keep-alive settings within hyper's Http builder (e.g., keep-alive timeout, max requests per connection) to balance performance benefits with resource management. Ensure keep-alive is configured appropriately for your application's traffic patterns and resource constraints within hyper.

• Threats Mitigated:

  • Denial of Service (DoS) attacks targeting hyper's connection handling (High Severity): Proper connection management in hyper prevents attackers from overwhelming the server by exhausting connection resources or holding connections open indefinitely.
  • Slowloris attacks against hyper (Medium to High Severity): Timeouts configured within hyper directly mitigate slowloris attacks by closing connections from clients that send requests slowly, preventing resource tie-up at the hyper layer.
  • Resource exhaustion within hyper due to connection leaks (Medium Severity): Connection pool limits and timeouts in hyper prevent resource exhaustion caused by excessive connection accumulation or poorly managed keep-alive connections within hyper's connection handling.

• Impact:

  • Significantly reduces the risk of DoS attacks, slowloris attacks, and resource exhaustion related to connection management within hyper.

• Currently Implemented:

  • Partially implemented. Basic timeouts might be configured, but hyper's connection pool settings and keep-alive configurations are likely using defaults and haven't been optimized for security and resource management.

• Missing Implementation:

  • Optimize hyper connection pool settings: Benchmark and tune hyper's connection pool parameters to find optimal values for resource utilization and performance under expected load.
  • Fine-tune timeouts in Hyper: Review and adjust timeouts configured within hyper's server builder to appropriate values for the application's use case and DoS mitigation.
  • Thorough keep-alive configuration in Hyper: Carefully configure keep-alive settings in hyper to balance performance and resource management, preventing potential connection leaks or resource exhaustion within hyper.
  • Monitoring of hyper connection metrics: Implement monitoring of hyper's connection pool usage and connection-related metrics to detect potential DoS attacks or resource issues at the hyper level.

Mitigation Strategy: Error Handling and Information Disclosure related to Hyper errors

• Description:

  1. Implement custom error handling for hyper::Error: Specifically handle errors of type hyper::Error that can occur during request processing, connection handling, or parsing within hyper. Prevent application crashes when hyper encounters errors.
  2. Sanitize error responses related to Hyper failures: When hyper encounters an error and your application needs to return an error response, ensure that the response does not expose internal details about hyper's internal state, configuration, or potential error messages that could reveal sensitive information. Provide generic error messages to clients in cases of hyper errors.
  3. Log detailed hyper::Error information securely: Log detailed information about hyper::Error instances, including the error kind and any associated context, to secure server-side logs for debugging and monitoring purposes. Ensure these logs are not publicly accessible.
  4. Use appropriate HTTP status codes for hyper errors: Return relevant HTTP status codes (e.g., 400 Bad Request for parsing errors, 500 Internal Server Error for unexpected hyper errors) to indicate the general nature of the error to the client without disclosing specific hyper details.

• Threats Mitigated:

  • Information Disclosure through hyper error messages (Medium Severity): Default error handling or verbose logging of hyper errors might inadvertently leak internal paths, configuration details, or stack traces related to hyper's operation.
  • Application instability due to unhandled hyper::Error (Medium Severity): Lack of proper error handling for hyper-specific errors can lead to application crashes or unexpected behavior when hyper encounters issues.

• Impact:

  • Reduces the risk of information disclosure through error responses related to hyper failures.
  • Reduces the risk of application instability caused by unhandled hyper::Error instances.

• Currently Implemented:

  • Partially implemented. Some custom error handling might exist for general application errors, but specific handling for hyper::Error and sanitization of error responses related to hyper failures are likely not fully implemented.

• Missing Implementation:

  • Dedicated error handling for hyper::Error: Implement specific error handling logic to catch and gracefully handle hyper::Error instances throughout the application.
  • Sanitization of error responses originating from Hyper: Ensure that error responses triggered by hyper errors are sanitized to prevent information leakage and provide generic error messages to clients.
  • Secure logging of hyper::Error details: Configure secure logging to capture detailed information about hyper::Error instances for debugging without exposing sensitive details in client-facing responses.
  • Consistent use of appropriate HTTP status codes for hyper errors: Ensure that appropriate HTTP status codes are consistently returned when hyper errors occur to provide meaningful feedback to clients without revealing internal details.