Additional Properties Too Permissive

  • Query id: 9f88c88d-824d-4d9a-b985-e22977046042
  • Query name: Additional Properties Too Permissive
  • Platform: OpenAPI
  • Severity: Low
  • Category: Insecure Configurations
  • CWE: 665
  • URL: Github

Description

Objects should not accept 'additionalProperties' if it is possible
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",
        "responses": {
          "200": {
            "schema": {
              "type": "object",
              "properties": {
                "id": {
                  "type": "string"
                },
                "name": {
                  "type": "string"
                }
              },
              "additionalProperties": "true"
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "MyObject": {
        "oneOf": [
          {
            "type": "object",
            "properties": {
              "id": {
                "type": "string"
              },
              "name": {
                "type": "string"
              }
            },
            "additionalProperties": "true"
          },
          {
            "type": "string",
            "additionalProperties": "false"
          }
        ]
      }
    }
  }
}
Positive test num. 2 - yaml file
openapi: 3.0.0
info:
  title: Simple API Overview
  version: 1.0.0
paths:
  "/":
    get:
      operationId: listVersionsv2
      summary: List API versions
      responses:
        '200':
          schema:
            type: object
            properties:
              id:
                type: string
              name:
                type: string
            additionalProperties: 'true'
components:
  schemas:
    MyObject:
      oneOf:
      - type: object
        properties:
          id:
            type: string
          name:
            type: string
        additionalProperties: 'true'
      - type: string
        additionalProperties: 'false'
Positive test num. 3 - json file
{
  "openapi": "3.0.0",
  "info": {
    "title": "Simple API Overview",
    "version": "1.0.0"
  },
  "paths": {
    "/": {
      "get": {
        "operationId": "listVersionsv2",
        "summary": "List API versions",
        "responses": {
          "200": {
            "schema": {
              "type": "object",
              "properties": {
                "id": {
                  "type": "string"
                },
                "name": {
                  "type": "string"
                }
              },
              "additionalProperties": "false"
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "MyObject": {
        "oneOf": [
          {
            "type": "object",
            "properties": {
              "id": {
                "type": "string"
              },
              "name": {
                "type": "string"
              }
            },
            "additionalProperties": "true"
          },
          {
            "type": "string",
            "additionalProperties": "true"
          }
        ]
      }
    }
  }
}

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
      responses:
        '200':
          schema:
            type: object
            properties:
              id:
                type: string
              name:
                type: string
            additionalProperties: 'false'
components:
  schemas:
    MyObject:
      oneOf:
      - type: object
        properties:
          id:
            type: string
          name:
            type: string
        additionalProperties: 'true'
      - type: string
        additionalProperties: 'true'
Positive test num. 5 - json file
{
  "openapi": "3.0.0",
  "info": {
    "title": "Simple API Overview",
    "version": "1.0.0"
  },
  "paths": {
    "/": {
      "get": {
        "operationId": "listVersionsv2",
        "summary": "List API versions",
        "responses": {
          "200": {
            "schema": {
              "type": "object",
              "properties": {
                "id": {
                  "type": "string"
                },
                "name": {
                  "type": "string"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "MyObject": {
        "oneOf": [
          {
            "type": "object",
            "properties": {
              "id": {
                "type": "string"
              },
              "name": {
                "type": "string"
              }
            },
            "additionalProperties": "true"
          },
          {
            "type": "string",
            "additionalProperties": "false"
          }
        ]
      }
    }
  }
}
Positive test num. 6 - yaml file
openapi: 3.0.0
info:
  title: Simple API Overview
  version: 1.0.0
paths:
  "/":
    get:
      operationId: listVersionsv2
      summary: List API versions
      responses:
        '200':
          schema:
            type: object
            properties:
              id:
                type: string
              name:
                type: string
components:
  schemas:
    MyObject:
      oneOf:
      - type: object
        properties:
          id:
            type: string
          name:
            type: string
        additionalProperties: 'true'
      - type: string
        additionalProperties: 'false'

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",
        "responses": {
          "200": {
            "schema": {
              "type": "object",
              "properties": {
                "id": {
                  "type": "string"
                },
                "name": {
                  "type": "string"
                }
              },
              "additionalProperties": "false"
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "MyObject": {
        "oneOf": [
          {
            "type": "object",
            "properties": {
              "id": {
                "type": "string"
              },
              "name": {
                "type": "string"
              }
            },
            "additionalProperties": "true"
          },
          {
            "type": "string",
            "additionalProperties": "false"
          }
        ]
      }
    }
  }
}
Negative test num. 2 - yaml file
openapi: 3.0.0
info:
  title: Simple API Overview
  version: 1.0.0
paths:
  "/":
    get:
      operationId: listVersionsv2
      summary: List API versions
      responses:
        '200':
          schema:
            type: object
            properties:
              id:
                type: string
              name:
                type: string
            additionalProperties: 'false'
components:
  schemas:
    MyObject:
      oneOf:
      - type: object
        properties:
          id:
            type: string
          name:
            type: string
        additionalProperties: 'true'
      - type: string
        additionalProperties: 'false'
Negative test num. 3 - json file
{
    "components": {},
    "info": {
      "description": "Swagger auto-generated from learnt schema for ves-io-s-gorman-s-gorman-sent4-http-load-balancer",
      "title": "ves-io-s-gorman-s-gorman-sent4-http-load-balancer",
      "version": "2023-06-21 17:30:59"
    },
    "openapi": "3.0.3",
    "paths": {
      "/": {
        "get": {
          "description": "Swagger auto-generated from learnt schema",
          "parameters": [
            {
              "description": "Integer",
              "in": "header",
              "name": "upgrade-insecure-requests",
              "schema": {
                "pattern": "-?\\d+",
                "type": "string"
              }
            }
          ]
        }
    },
    "servers": [
      {
        "url": "http://sent4.volterra.plutometal.com"
      },
      {
        "url": "https://sent4.volterra.plutometal.com"
      }
    ]
  }
}