Undefined Scope 'securityScheme' On 'security' Field On Operations

• Query id: 462d6a1d-fed9-4d75-bb9e-3de902f35e6e
• Query name: Undefined Scope 'securityScheme' On 'security' Field On Operations
• Platform: OpenAPI
• Severity: Low
• Category: Access Control
• CWE: 284
• URL: Github

Description

Using a scope on security of operations that is undefined on 'securityScheme' can be defined by an attacker
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - json file

{
  "openapi": "3.0.0",
  "info": {
    "title": "Simple API overview",
    "version": "1.0.0"
  },
  "paths": {
    "/": {
      "get": {
        "operationId": "listVersionsv2",
        "summary": "List API versions",
        "security": {
          "oAuth2AuthCodeNeg2": [
            "read:api",
            "error:api"
          ]
        },
        "responses": {
          "200": {
            "description": "200 response",
            "content": {
              "application/json": null
            }
          }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "oAuth2AuthCodeNeg2": {
        "type": "oauth2",
        "description": "For more information, see https://api.my.company.com/docs/oauth",
        "flows": {
          "authorizationCode": {
            "authorizationUrl": "https://api.my.company.com/oauth/authorize",
            "tokenUrl": "https://api.my.company.com/oauth/token",
            "scopes": {
              "read:api": "read your apis",
              "admin:api": "admin scope"
            }
          },
          "password": {
            "tokenUrl": "https://api.my.company.com/oauth/token",
            "scopes": {
              "write:api": "write your apis"
            }
          }
        }
      }
    }
  }
}

Positive test num. 2 - json file

{
  "openapi": "3.0.0",
  "info": {
    "title": "Simple API overview",
    "version": "1.0.0"
  },
  "paths": {
    "/": {
      "get": {
        "operationId": "listVersionsv2",
        "summary": "List API versions",
        "security": [
          {
            "oAuth2AuthCodeNeg2": [
              "error:api",
              "write:api"
            ]
          }
        ],
        "responses": {
          "200": {
            "description": "200 response",
            "content": {
              "application/json": null
            }
          }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "oAuth2AuthCodeNeg2": {
        "type": "oauth2",
        "description": "For more information, see https://api.my.company.com/docs/oauth",
        "flows": {
          "authorizationCode": {
            "authorizationUrl": "https://api.my.company.com/oauth/authorize",
            "tokenUrl": "https://api.my.company.com/oauth/token",
            "scopes": {
              "read:api": "read your apis",
              "admin:api": "admin scope"
            }
          },
          "password": {
            "tokenUrl": "https://api.my.company.com/oauth/token",
            "scopes": {
              "write:api": "write your apis"
            }
          }
        }
      }
    }
  }
}

Positive test num. 3 - yaml file

openapi: 3.0.0
info:
  title: Simple API overview
  version: 1.0.0
paths:
  "/":
    get:
      operationId: listVersionsv2
      summary: List API versions
      security:
        oAuth2AuthCodeNeg2:
        - read:api
        - error:api
      responses:
        '200':
          description: 200 response
          content:
            application/json:
components:
  securitySchemes:
    oAuth2AuthCodeNeg2:
      type: oauth2
      description: For more information, see https://api.my.company.com/docs/oauth
      flows:
        authorizationCode:
          authorizationUrl: https://api.my.company.com/oauth/authorize
          tokenUrl: https://api.my.company.com/oauth/token
          scopes:
            read:api: read your apis
            admin:api: admin scope
        password:
          tokenUrl: https://api.my.company.com/oauth/token
          scopes:
            write:api: write your apis

Positive test num. 4 - yaml file

openapi: 3.0.0
info:
  title: Simple API overview
  version: 1.0.0
paths:
  "/":
    get:
      operationId: listVersionsv2
      summary: List API versions
      security:
      - oAuth2AuthCodeNeg2:
        - error:api
        - write:api
      responses:
        '200':
          description: 200 response
          content:
            application/json:
components:
  securitySchemes:
    oAuth2AuthCodeNeg2:
      type: oauth2
      description: For more information, see https://api.my.company.com/docs/oauth
      flows:
        authorizationCode:
          authorizationUrl: https://api.my.company.com/oauth/authorize
          tokenUrl: https://api.my.company.com/oauth/token
          scopes:
            read:api: read your apis
            admin:api: admin scope
        password:
          tokenUrl: https://api.my.company.com/oauth/token
          scopes:
            write:api: write your apis

Code samples without security vulnerabilities

Negative test num. 1 - json file

{
  "openapi": "3.0.0",
  "info": {
    "title": "Simple API overview",
    "version": "1.0.0"
  },
  "paths": {
    "/": {
      "get": {
        "operationId": "listVersionsv2",
        "summary": "List API versions",
        "security": [
          {
            "oAuth2AuthCodeNeg2": [
              "read:api",
              "write:api"
            ]
          }
        ],
        "responses": {
          "200": {
            "description": "200 response",
            "content": {
              "application/json": null
            }
          }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "oAuth2AuthCodeNeg2": {
        "type": "oauth2",
        "description": "For more information, see https://api.my.company.com/docs/oauth",
        "flows": {
          "authorizationCode": {
            "authorizationUrl": "https://api.my.company.com/oauth/authorize",
            "tokenUrl": "https://api.my.company.com/oauth/token",
            "scopes": {
              "read:api": "read your apis",
              "admin:api": "admin scope"
            }
          },
          "password": {
            "tokenUrl": "https://api.my.company.com/oauth/token",
            "scopes": {
              "write:api": "write your apis"
            }
          }
        }
      }
    }
  }
}

Negative test num. 2 - json file

{
  "openapi": "3.0.0",
  "info": {
    "title": "Simple API overview",
    "version": "1.0.0"
  },
  "paths": {
    "/": {
      "get": {
        "operationId": "listVersionsv2",
        "summary": "List API versions",
        "security": {
          "oAuth2AuthCodeNeg2": [
            "read:api",
            "write:api"
          ]
        },
        "responses": {
          "200": {
            "description": "200 response",
            "content": {
              "application/json": null
            }
          }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "oAuth2AuthCodeNeg2": {
        "type": "oauth2",
        "description": "For more information, see https://api.my.company.com/docs/oauth",
        "flows": {
          "authorizationCode": {
            "authorizationUrl": "https://api.my.company.com/oauth/authorize",
            "tokenUrl": "https://api.my.company.com/oauth/token",
            "scopes": {
              "read:api": "read your apis",
              "admin:api": "admin scope"
            }
          },
          "password": {
            "tokenUrl": "https://api.my.company.com/oauth/token",
            "scopes": {
              "write:api": "write your apis"
            }
          }
        }
      }
    }
  }
}

Negative test num. 3 - yaml file

openapi: 3.0.0
info:
  title: Simple API overview
  version: 1.0.0
paths:
  "/":
    get:
      operationId: listVersionsv2
      summary: List API versions
      security:
      - oAuth2AuthCodeNeg2:
        - read:api
      responses:
        '200':
          description: 200 response
          content:
            application/json:
components:
  securitySchemes:
    oAuth2AuthCodeNeg2:
      type: oauth2
      description: For more information, see https://api.my.company.com/docs/oauth
      flows:
        authorizationCode:
          authorizationUrl: https://api.my.company.com/oauth/authorize
          tokenUrl: https://api.my.company.com/oauth/token
          scopes:
            read:api: read your apis

Negative test num. 4 - yaml file

openapi: 3.0.0
info:
  title: Simple API overview
  version: 1.0.0
paths:
  "/":
    get:
      operationId: listVersionsv2
      summary: List API versions
      security:
      - oAuth2AuthCodeNeg2:
        - read:api
      responses:
        '200':
          description: 200 response
          content:
            application/json:
components:
  securitySchemes:
    oAuth2AuthCodeNeg2:
      type: oauth2
      description: For more information, see https://api.my.company.com/docs/oauth
      flows:
        authorizationCode:
          authorizationUrl: https://api.my.company.com/oauth/authorize
          tokenUrl: https://api.my.company.com/oauth/token
          scopes:
            read:api: read your apis