Sending credentials as cleartext allowed

Average severity: High

Description

The securityScheme of the API allows to set security requirements that accept user credentials sent in cleartext over an unencrypted channel. Attackers can easily intercept API calls and retrieve the credentials. They can then use the credentials to make other API calls.

This is a potential risk, because the definition is in the security scheme of the API, not in the security requirements. However, it easily turns into an actual risk when the unsafe method is used in a security requirement.

Example

The following is an example of how this type of risk could look in your API definition:

  "schemes": [
    "http"
  ],
  ...
  "securityDefinitions": {
    "regularSecurity": {
      "type": "basic"
    }
  },
  ...
  "security": [
    {
      "regularSecurity": []
    }
  ],
  ...
}

The security section defines that the API is protected with basic authentication (username and password). The schemes section sets HTTP as the supported transportation protocol. This means that the API could accept an API call over an unencrypted HTTP connection, and expects it to have the username and password in the clear.

Possible exploit scenario

Attackers can intercept the credentials simply by listening to the network traffic in a public WiFi network. They could also use a traffic logging tool on a smartphone, computer, or browser, or sniff the traffic in the network to get the credentials.

Remediation

At the very least, set  schemes to support HTTPS only so that all traffic is encrypted.

You could also improve the security of the authentication method. The OAuth 2.0 accessCode flow is considered the most secure way to provide API authorization for OpenAPI Specification v2.

  "schemes": [
    "https"
  ],
  ...
  "securityDefinitions": {
    "OAuth2": {
      "type": "oauth2",
      "flow": "accessCode",
      "scopes": {
        "readOnly": "read objects in your account"
      },
      "authorizationUrl": "https://example.com/oauth/authorize",
      "tokenUrl": "https://example.com/oauth/token", 
    }
  },
  ...
  "security" : [
    "OAuth2": [ "readOnly" ]
  ]
}

 


Get API Security news directly in your Inbox.

By clicking Subscribe you agree to our Data Policy