Skip to content

Latest commit

 

History

History
80 lines (68 loc) · 6.88 KB

vulnerabilities-workflow-1.md

File metadata and controls

80 lines (68 loc) · 6.88 KB

Vulnerability List for OpenAPI analysis Project

This document outlines a vulnerability identified in the OpenAPI analysis project.

Vulnerability: Incorrect Security Enforcement due to Improper External Reference Resolution in Security Definitions

  • Description:

    1. An attacker crafts an OpenAPI specification (main_spec.yml) that defines security schemes in an external file (external_security.yml) and references them in the securityDefinitions section using $ref.
    2. This specification (main_spec.yml) is processed by the go-openapi/analysis library.
    3. Due to improper external reference resolution in the securityDefinitions section, the library fails to correctly analyze and represent the security schemes.
    4. A security tool or system that relies on go-openapi/analysis to generate security enforcement logic (like authentication/authorization middleware) processes the flawed analysis result.
    5. The generated security enforcement is incomplete or incorrect, failing to enforce the intended security policies defined by the external security schemes.
    6. Consequently, API endpoints intended to be protected by the externally defined security schemes become accessible without proper authentication or authorization.

  • Impact:

    • APIs may be exposed with weaker security than intended.
    • Unauthorized access to API endpoints, potentially leading to data breaches or other security violations.
    • Misinterpretation of API security policies by developers and security tools, leading to incorrect security assumptions.

  • Vulnerability Rank: high

  • Currently Implemented Mitigations:

    • No mitigations are currently implemented within the project to address improper external reference resolution in security definitions. The project primarily focuses on OpenAPI specification analysis and does not include security enforcement mechanisms.

  • Missing Mitigations:

    • Implement robust and accurate external reference resolution specifically for the securityDefinitions section of OpenAPI specifications.
    • Add validation to ensure that all external references within securityDefinitions are correctly resolved and point to valid security scheme definitions.
    • Develop and include security-focused test cases that specifically verify the correct handling of external references in security schemes, ensuring that analysis accurately reflects the intended security policies.

  • Preconditions:

    • An OpenAPI specification that utilizes external references within the securityDefinitions section.
    • The specification is processed by the go-openapi/analysis library.
    • The output of the analysis is used by a tool or system to generate and apply API security enforcement.

  • Source Code Analysis:

    • Vulnerability Location: The vulnerability is present in the parsing and reference resolution logic within analyzer.go, specifically in how the go-openapi/analysis library handles $ref keywords, especially within the securityDefinitions section of OpenAPI specifications. The code related to reference analysis is primarily in the referenceAnalysis struct and its methods. The main parsing logic resides within the Spec.initialize() function.

    • Trigger Mechanism: The vulnerability is triggered when the go-openapi/analysis library processes an OpenAPI specification that includes an external $ref in the securityDefinitions section. If the library's reference resolution logic is incomplete or flawed for security definitions, it will fail to correctly analyze and represent the security schemes, leading to incorrect security analysis results.

    • Code Flow:

      1. The Spec.initialize() function in analyzer.go is the entry point for specification analysis. It parses different parts of the OpenAPI specification, including securityDefinitions.
      2. During parsing, when the code encounters a $ref within securityDefinitions, it attempts to resolve it using the general reference resolution mechanisms of the library (within referenceAnalysis methods like addRef, addSchemaRef, addResponseRef, addParamRef).
      3. However, the provided code in analyzer.go does not contain specific logic to handle external references in securityDefinitions differently or with special attention to security implications. The generic reference resolution logic might not be sufficient for correctly interpreting security schemes defined externally.
      4. If the external reference in securityDefinitions is not correctly resolved and analyzed, the go-openapi/analysis library will produce an incomplete or incorrect representation of the API's security configuration.
      5. Downstream tools that rely on the output of go-openapi/analysis for security enforcement will then generate flawed security configurations, potentially leading to security bypasses.

  • Security Test Case:

    1. Create two YAML files: main_spec.yml and external_security.yml.
      • external_security.yml: 
        securitySchemes:
  ExternalAPIKey:
    type: apiKey
    in: header
    name: X-External-API-Key
      • main_spec.yml: 
        swagger: "2.0"
info:
  title: Test API with External Security
  version: "1.0.0"
securityDefinitions:
  $ref: 'external_security.yml#/securitySchemes'
security:
  - ExternalAPIKey: []
paths:
  /protected:
    get:
      responses:
        200:
          description: Success
    2. Host main_spec.yml and external_security.yml in a location accessible to the testing tool or environment.
    3. Utilize a security tool that leverages go-openapi/analysis for OpenAPI specification processing and generates API security enforcement (e.g., authentication middleware). Configure this tool to load and process main_spec.yml.
    4. Inspect the generated security enforcement configuration or code. Verify if the ExternalAPIKey security scheme is correctly recognized and implemented. Specifically, check if the generated authentication middleware is configured to enforce the requirement of the X-External-API-Key header for the /protected endpoint.
    5. Send a GET request to the /protected endpoint of the API without including the X-External-API-Key header in the request.
    6. Observe the application's response.
      • Vulnerable Result: If the request succeeds and returns a 200 OK response, it indicates that the security enforcement is missing or ineffective, confirming the vulnerability. The request should have been blocked due to the missing API key.
      • Mitigated Result: If the request is blocked and returns a 401 Unauthorized error, it indicates that the security enforcement is correctly applied, and the vulnerability is likely mitigated.