Threat Model Analysis for tokio-rs/axum

Threat: Unvalidated Path Parameter Injection

Description: An attacker manipulates path parameters in the URL to access unauthorized resources or trigger unintended application behavior. For example, an attacker might change /users/{id} to /users/../admin if path traversal is not prevented.
Impact: Unauthorized access to sensitive data, modification of data, or execution of privileged actions. Can lead to data breaches, privilege escalation, and application compromise.
Affected Axum Component: axum::extract::Path extractor, Route handlers.
Risk Severity: High
Mitigation Strategies:
- Always validate and sanitize path parameters within handler functions.
- Use allowlists for acceptable characters and formats in path parameters.
- Avoid directly using path parameters to construct file paths or system commands without strict validation.
- Implement proper authorization checks based on validated path parameters.

Threat: Unvalidated Query Parameter Injection

Description: An attacker injects malicious code or data through query parameters in the URL. This could be used for various attacks like SQL injection (if query parameters are used in database queries without sanitization), cross-site scripting (XSS) if reflected in responses, or manipulating application logic.
Impact: Data breaches, application malfunction, cross-site scripting vulnerabilities, denial of service.
Affected Axum Component: axum::extract::Query extractor, Route handlers.
Risk Severity: High
Mitigation Strategies:
- Validate and sanitize all query parameters within handler functions.
- Use parameterized queries or ORM frameworks to prevent SQL injection.
- Encode output properly to prevent XSS vulnerabilities if query parameters are reflected in responses.
- Limit the size and complexity of query parameters to prevent denial of service.

Threat: Authentication Bypass in Custom Middleware

Description: Flaws in custom authentication middleware logic allow attackers to bypass authentication checks and gain unauthorized access to protected resources. This could be due to logic errors, incorrect token validation, or improper session management within the middleware.
Impact: Unauthorized access to sensitive data and functionalities, privilege escalation, complete application compromise.
Affected Axum Component: Custom Axum middleware implementing authentication logic, axum::middleware::Next.
Risk Severity: Critical
Mitigation Strategies:
- Thoroughly review and test custom authentication middleware for logic flaws and bypass vulnerabilities.
- Use established and well-vetted authentication libraries and patterns where possible.
- Implement robust token validation and session management.
- Perform regular security audits and penetration testing of authentication mechanisms.