Skip to content

Latest commit

 

History

History
42 lines (33 loc) · 4.36 KB

attack-surface.md

File metadata and controls

42 lines (33 loc) · 4.36 KB

Attack Surface Analysis for tokio-rs/axum

Attack Surface: Overly Permissive Route Definitions

  • Description: Routes that are too broad or lack sufficient validation can expose unintended handlers or resources to unauthorized access.
    • How Axum Contributes: Axum's flexible routing system, while powerful, requires careful configuration to avoid unintended exposure. Features like wildcards (*), path parameters, and nested routers can easily be misused, directly leading to this vulnerability.
    • Example: A route defined as /users/{user_id} without validating user_id could allow an attacker to access any user's data. /admin/* without authentication.
    • Impact: Unauthorized access to sensitive data, execution of privileged operations, potential for complete system compromise.
    • Risk Severity: Critical
    • Mitigation Strategies:
      • Developers: Use the most specific route definitions possible. Avoid broad wildcards. Implement robust input validation within handlers for all data extracted from the path. Use authentication and authorization middleware before sensitive handlers. Regularly audit route definitions.

Attack Surface: Extractor-Based Input Validation Bypass

  • Description: Relying solely on Axum's extractors for type safety without performing subsequent input validation can allow malicious data to be processed.
    • How Axum Contributes: Axum's extractors are a core feature for handling request data. The vulnerability arises from the misunderstanding that extractors perform validation beyond basic deserialization. This is a direct consequence of how Axum's extractors are designed and used.
    • Example: An extractor deserializes a JSON payload, but a string field contains an XSS payload. A Path extractor retrieves a user ID, but the ID is not checked for validity or authorization.
    • Impact: XSS, SQL injection, command injection, other application-specific vulnerabilities.
    • Risk Severity: High
    • Mitigation Strategies:
      • Developers: Always perform thorough input validation after using an extractor. Use validation libraries. Sanitize data before use. Implement size limits on extracted data.

Attack Surface: Middleware Misconfiguration (Ordering)

  • Description: Incorrect middleware ordering can create security vulnerabilities, bypassing security checks.
    • How Axum Contributes: Axum's middleware system and its execution order are fundamental to its request handling pipeline. Incorrect ordering is a direct misconfiguration of Axum's features.
    • Example: Placing authentication middleware after logging middleware, leading to sensitive data being logged before authentication.
    • Impact: Bypass of security controls (authentication, authorization), information disclosure.
    • Risk Severity: High
    • Mitigation Strategies:
      • Developers: Carefully plan the order of middleware. Place security-related middleware (authentication, authorization, input validation) before other middleware. Thoroughly test the middleware stack.

Attack Surface: Denial of Service (DoS) via Request Handling (Extractor Limits)

  • Description: Attackers can exploit Axum's request handling, specifically through extractors, to exhaust server resources.
    • How Axum Contributes: While Axum uses asynchronous processing, the lack of limits within Axum's extractors directly contributes to this vulnerability. Axum provides the mechanism (extractors) that, without proper configuration, enables the attack.
    • Example: An attacker sending a very large JSON payload to an endpoint using axum::Json without any size limits (e.g., ContentLengthLimit) configured.
    • Impact: Service unavailability, degraded performance.
    • Risk Severity: High
    • Mitigation Strategies:
      • Developers: Use ContentLengthLimit (or similar extractors with built-in limits) to restrict the size of request bodies within Axum. This is a mitigation directly within Axum's control.