mitigations.md

Mitigation Strategies Analysis for ankane/searchkick

Mitigation Strategy: Sanitize User Input for Search Queries

• Description:
  1. Identify all user inputs that are incorporated into Searchkick search queries (e.g., from search bars, filter inputs).
  2. Before passing user input to Searchkick, sanitize it to prevent Elasticsearch injection attacks.
  3. Use appropriate escaping techniques for the Lucene query syntax that Searchkick uses internally. This often involves escaping characters like +, -, =, >, <, !, (, ), {, }, [, ], ^, ", ~, *, ?, :, \, /.
  4. Utilize built-in sanitization functions provided by your programming language or framework, or consider using a dedicated query parser library to ensure robust sanitization.
  5. Test sanitization by attempting common injection payloads through your application's search interface and verifying that Searchkick processes them safely without unintended query modifications.
• List of Threats Mitigated:
  • Elasticsearch Injection (High Severity): Attackers can manipulate search queries via user input to bypass intended search logic, potentially access unauthorized data, or cause errors in Elasticsearch.
• Impact: High - Significantly reduces the risk of Elasticsearch injection attacks originating from user input processed by Searchkick.
• Currently Implemented: Partial - Basic escaping is applied to the main search bar input within the application's frontend before sending the query to the backend which uses Searchkick.
• Missing Implementation: Sanitization needs to be extended to all user-controlled inputs that influence Searchkick queries, including advanced filters, sorting parameters, and any other user-configurable search options. Backend sanitization within the application code using Searchkick should be implemented to ensure defense in depth.

Mitigation Strategy: Validate Search Parameters Passed to Searchkick

• Description:
  1. Define a strict whitelist of allowed search parameters that your application intends to pass to Searchkick (e.g., allowed fields for searching, sorting, filtering).
  2. Implement validation logic in your application code before invoking Searchkick to check if incoming search requests adhere to this whitelist.
  3. Reject or sanitize requests that contain parameters not on the whitelist or parameters with invalid values (e.g., unexpected data types, invalid field names).
  4. Ensure that field names used in search parameters correspond to fields that are actually indexed by Searchkick and intended to be user-searchable.
  5. For sort orders, validate against a predefined list of sortable fields and allowed directions (ascending/descending).
  6. For filters, validate filter names and the expected format and values of filter criteria before passing them to Searchkick.
• List of Threats Mitigated:
  • Elasticsearch Injection (Medium Severity): Prevents attackers from manipulating search behavior by injecting unexpected or malicious parameters through Searchkick.
  • Information Disclosure (Low Severity): Reduces the risk of accidentally exposing internal data structures or fields not intended for public search by limiting the parameters that can be used in Searchkick queries.
• Impact: Medium - Reduces the attack surface by limiting the controllable parameters passed to Searchkick, preventing unexpected query modifications and potential information leaks.
• Currently Implemented: Partial - Field names used in basic search queries are validated against a predefined list in the backend service that uses Searchkick.
• Missing Implementation: Validation for sort orders, filter parameters, and more complex search options passed to Searchkick is not fully implemented. Comprehensive validation needs to be added for all parameters used with Searchkick.

Mitigation Strategy: Limit Query Complexity in Searchkick Usage

• Description:
  1. Analyze typical user search patterns and determine reasonable limits for query complexity within your application's Searchkick usage.
  2. Implement limits in your application code that restrict the complexity of queries constructed and executed via Searchkick. This could include:
     • Limiting the number of clauses combined in boolean queries built using Searchkick.
     • Restricting the number of filters applied in a single Searchkick search.
     • Setting timeouts for Searchkick search operations to prevent long-running queries.
  3. Configure these limits within your application logic that interacts with Searchkick.
  4. Return user-friendly error messages if a search query exceeds complexity limits, indicating that the query is too complex and needs to be simplified.
• List of Threats Mitigated:
  • Denial of Service (DoS) (Medium Severity): Prevents attackers from crafting excessively complex search queries through the application's search interface that could consume excessive Elasticsearch resources via Searchkick and degrade performance.
• Impact: Medium - Mitigates resource exhaustion caused by overly complex queries initiated through Searchkick, improving system stability and resilience against DoS attempts.
• Currently Implemented: No - Query complexity limits are not currently implemented in the application code that uses Searchkick.
• Missing Implementation: Need to implement query complexity limits within the application's search logic that utilizes Searchkick. This could involve limiting the number of combined search terms, filters, or other complexity factors when constructing Searchkick queries.

Mitigation Strategy: Control Searchable Fields in Searchkick Models

• Description:
  1. Explicitly define which attributes of your application's models are made searchable by Searchkick.
  2. Utilize Searchkick's configuration options within your models (e.g., the searchable method) to precisely specify which attributes should be indexed and searchable.
  3. Avoid making sensitive attributes searchable through Searchkick unless absolutely necessary and with robust access controls in place at other levels (e.g., Elasticsearch index/field level security, application-level authorization).
  4. Carefully consider which fields are included in Searchkick search results and ensure that no sensitive data is inadvertently returned to unauthorized users.
  5. Regularly review and update the list of searchable fields in your Searchkick models as data requirements and security considerations evolve.
• List of Threats Mitigated:
  • Information Disclosure (Medium Severity): Prevents unintentional exposure of sensitive data through search results by carefully controlling which fields are made searchable and retrievable via Searchkick.
• Impact: Medium - Reduces the risk of data exposure by limiting the scope of data made searchable through Searchkick to only what is intended and necessary.
• Currently Implemented: Yes - Searchable fields are explicitly defined in Searchkick models using the searchable method.
• Missing Implementation: A periodic review process for searchable fields in Searchkick models is needed to ensure they remain appropriate and do not inadvertently expose new sensitive information as the application evolves.

Mitigation Strategy: Regularly Update Searchkick Gem

• Description:
  1. Establish a process for regularly updating the Searchkick gem to the latest stable version.
  2. Monitor security advisories and release notes specifically for the Searchkick gem for any reported vulnerabilities or security patches.
  3. Apply security patches and updates for Searchkick promptly after they are released.
  4. Test Searchkick updates in a staging environment before deploying to production to ensure compatibility with your application and Elasticsearch version and to verify that the update does not introduce regressions.
  5. Consider using automated dependency update tools to help track and manage Searchkick gem updates.
• List of Threats Mitigated:
  • Exploitation of Known Vulnerabilities in Searchkick (High Severity): Prevents attackers from exploiting known security vulnerabilities that may exist in outdated versions of the Searchkick gem itself.
• Impact: High - Essential for maintaining a secure application by addressing known vulnerabilities within the Searchkick gem and reducing the attack surface related to Searchkick.
• Currently Implemented: Partial - Dependency updates are performed periodically, but a formal process specifically for monitoring Searchkick security advisories and ensuring timely updates is missing.
• Missing Implementation: Need to establish a formal process for monitoring Searchkick security advisories and ensuring that the Searchkick gem is updated regularly to the latest secure version.

Mitigation Strategy: Dependency Scanning for Searchkick and its Dependencies

• Description:
  1. Integrate dependency scanning tools into your development workflow (e.g., CI/CD pipeline) to specifically scan the Searchkick gem and its dependencies for known security vulnerabilities.
  2. Use tools like bundler-audit (for Ruby projects) or similar tools that can identify vulnerabilities in Ruby gems, including Searchkick and its transitive dependencies.
  3. Configure dependency scanning to run regularly (e.g., on every commit or daily) to proactively detect new vulnerabilities.
  4. Address any vulnerabilities identified by dependency scanning tools promptly by updating Searchkick or its vulnerable dependencies to patched versions.
  5. Use dependency scanning reports to prioritize security fixes related to Searchkick and its dependency chain.
• List of Threats Mitigated:
  • Exploitation of Known Vulnerabilities in Searchkick Dependencies (High Severity): Proactively identifies known vulnerabilities in the dependencies of the Searchkick gem, allowing for timely remediation before they can be exploited through Searchkick.
• Impact: High - Significantly reduces the risk of exploiting known vulnerabilities in Searchkick's dependency chain by proactively identifying and addressing them.
• Currently Implemented: Yes - Dependency scanning using bundler-audit is integrated into the CI/CD pipeline and includes scanning for vulnerabilities in all project dependencies, including Searchkick.
• Missing Implementation: Regularly review dependency scanning reports specifically for Searchkick and its dependencies and ensure timely remediation of any identified vulnerabilities. Improve automation of vulnerability remediation for Searchkick dependencies where possible.