attack-surface.md

Attack Surface Analysis for higherorderco/bend

Attack Surface: Server-Side Template Injection (SSTI) via Bend's Template Engine Integration

• Description: If bend provides built-in or strongly recommended template engine integrations, and these integrations do not enforce or guide developers towards secure templating practices, it can lead to Server-Side Template Injection (SSTI) vulnerabilities. This occurs when user-controlled data is improperly embedded into templates without sufficient sanitization, allowing attackers to inject malicious template code and achieve remote code execution.
• Bend Contribution: bend's design choices regarding template engine integration directly contribute to this attack surface. If bend promotes or defaults to insecure template usage (e.g., lacking auto-escaping by default, insufficient documentation on secure templating), it increases the risk of SSTI in applications built with it. A poorly designed or documented template integration API within bend can also make secure templating harder for developers.
• Example: bend's documentation examples show template rendering using direct variable substitution without emphasizing or demonstrating proper escaping. Developers following these examples might unknowingly create SSTI vulnerabilities. If bend provides a helper function for template rendering that doesn't automatically escape output, it directly contributes to the risk.
• Impact: Remote code execution, full server compromise, data breaches, denial of service.
• Risk Severity: Critical.
• Mitigation Strategies:
  • Secure Template Engine Choice & Configuration (Bend Framework Developers): If bend integrates with a template engine, choose one with strong security features, including automatic output escaping by default. Configure the integration to enforce secure defaults.
  • Secure Templating API & Documentation (Bend Framework Developers): Design bend's template integration API to encourage secure usage. Provide clear and prominent documentation and examples demonstrating secure templating practices, including context-aware escaping and input validation. Warn against insecure practices.
  • Auto-Escaping in Templates (Application Developers): When using templates in bend applications, utilize template engines with auto-escaping enabled by default. If auto-escaping is not sufficient, use context-aware escaping functions provided by the template engine.
  • Input Validation (Application Developers): Validate and sanitize user input before passing it to the template engine to minimize the risk of malicious injection.

Attack Surface: Insecure Default Configurations within Bend Framework

• Description: bend framework itself might ship with insecure default configurations that are enabled out-of-the-box. These insecure defaults could expose sensitive information, weaken security controls, or introduce vulnerabilities if not explicitly overridden by developers during deployment.
• Bend Contribution: The choice of default configurations within bend is a direct contribution to the attack surface. Insecure defaults directly increase the risk for all applications built using bend unless developers are aware of and actively change them.
• Example: bend's default configuration might enable a debug mode in production that exposes detailed error messages, internal application paths, or even allows interactive debugging endpoints. Another example could be overly permissive default CORS settings that allow unintended cross-origin access.
• Impact: Information disclosure, unauthorized access, cross-site scripting (XSS), cross-site request forgery (CSRF), potentially remote code execution depending on the nature of the insecure default.
• Risk Severity: High to Critical (depending on the specific insecure default).
• Mitigation Strategies:
  • Secure Defaults (Bend Framework Developers): Prioritize security when setting default configurations for bend. Ensure defaults are secure and suitable for production environments. Disable debug features and enable restrictive security settings by default.
  • Configuration Hardening Guidance (Bend Framework Developers): Provide clear and prominent documentation guiding developers on how to harden bend configurations for production deployments. Explicitly list and explain any potentially insecure defaults and how to change them. Offer secure configuration templates or best practice examples.
  • Configuration Audits (Application Developers): Thoroughly review and audit bend's default configurations and ensure they are appropriate for the application's security requirements. Actively override any insecure defaults with secure production settings.
  • Principle of Least Privilege (Application Developers): Configure the bend application with the minimum necessary permissions and features enabled. Disable any unnecessary features or endpoints, especially in production.

Attack Surface: Bend Framework API Design Leading to Insecure Custom Middleware

• Description: If bend's API for creating and integrating custom middleware is poorly designed, unclear, or lacks sufficient security guidance, it can indirectly lead to developers creating insecure middleware components. This includes issues like authentication/authorization bypasses, data leaks in middleware, or performance bottlenecks due to inefficient middleware.
• Bend Contribution: The design and documentation of bend's middleware API directly influence the security of custom middleware developed using it. A poorly designed API or inadequate security guidance increases the likelihood of developers making security mistakes when implementing middleware.
• Example: If bend's middleware API makes it difficult to correctly access request context or response objects, developers might resort to insecure workarounds. If the documentation lacks clear examples of secure middleware implementation (e.g., proper error handling, secure session management within middleware), developers are more likely to create vulnerable middleware.
• Impact: Unauthorized access, data breaches, data manipulation, denial of service, depending on the vulnerabilities introduced in custom middleware.
• Risk Severity: High.
• Mitigation Strategies:
  • Secure Middleware API Design (Bend Framework Developers): Design a clear, intuitive, and secure middleware API. Ensure it provides necessary tools and patterns for secure middleware development.
  • Comprehensive Security Guidance for Middleware (Bend Framework Developers): Provide detailed documentation and examples on how to develop secure middleware using bend. Cover common security concerns in middleware, such as authentication, authorization, input validation, output encoding, and error handling.
  • Code Reviews & Security Testing for Middleware (Application Developers): Thoroughly review and security test all custom middleware components developed for bend applications. Pay close attention to authentication, authorization, and data handling logic within middleware.
  • Use Established Libraries (Application Developers): Encourage and facilitate the use of well-vetted and established security libraries for common middleware tasks (e.g., JWT validation, rate limiting) within bend applications, rather than encouraging developers to implement security-sensitive logic from scratch.