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Lack of data validation - URL

Need​

Implementation of proper data validation for URL parameters

Context​

  • Usage of Scala for building scalable and functional applications
  • Usage of play.api.mvc for handling HTTP requests and responses in Play Framework
  • Usage of DocumentService for managing and manipulating documents

Description​

Non compliant code​

import play.api.mvc._

class DocumentController extends Controller {

  def getDocuments(date: String) = Action {
    val documents = DocumentService.getDocumentsByDate(date)
    Ok(documents)
  }
}

The getDocuments function in the DocumentController class is vulnerable because it accepts a date parameter from the URL and uses it to fetch documents without performing any form of validation or authentication.

This means that any user can simply provide a date as a parameter in the URL to retrieve all documents sent on that date. For example, a malicious user could use a URL like http://example.com/getDocuments?date=2022-01-01 to retrieve all documents sent on January 1, 2022.

The issue here is that there's no check to ensure that the user making the request has the necessary permissions to access the requested documents. This exposes sensitive information and violates the principle of least privilege, which states that a user should only have access to the resources they need to perform their tasks.

The vulnerable code is located in the getDocuments method of the DocumentController class. The method takes a date parameter from the URL and passes it directly to the getDocumentsByDate method of the DocumentService class. The returned documents are then sent back to the user as a response.

Steps​

  • Implement input validation to ensure that the 'date' parameter is in the expected format.
  • Validate the 'date' parameter to prevent any malicious input or unexpected behavior.
  • Consider using a regular expression or a date parsing library to validate the 'date' parameter.
  • If the 'date' parameter is not valid, return an appropriate error response instead of processing the request.
  • Ensure that the user accessing the endpoint has the necessary permissions to view the documents.
  • Implement authentication and authorization mechanisms to restrict access to sensitive information.
  • Consider implementing rate limiting or other security measures to prevent abuse of the endpoint.
  • Regularly review and update the validation logic to adapt to new security threats and vulnerabilities.

Compliant code​

import play.api.mvc._
import java.time.LocalDate
import java.time.format.DateTimeParseException

class DocumentController extends Controller {

  def getDocuments(date: String) = Action {
    try {
      LocalDate.parse(date)
      val documents = DocumentService.getDocumentsByDate(date)
      Ok(documents)
    } catch {
      case e: DateTimeParseException => BadRequest("Invalid date format")
    }
  }
}

The updated code now includes a validation step for the 'date' parameter. This is done using the LocalDate.parse(date) method, which will throw a DateTimeParseException if the date is not in a valid format.

If the date is valid, the documents for that date are retrieved and returned as before. If the date is not valid, a BadRequest response is returned with a message indicating that the date format is invalid.

This validation step helps to prevent any malicious input or unexpected behavior by ensuring that the 'date' parameter is in the expected format before processing the request.

Please note that this code does not include any authentication or authorization mechanisms, or any rate limiting or other security measures. These should be implemented as appropriate for your application to further enhance security.

Also, it's important to regularly review and update the validation logic to adapt to new security threats and vulnerabilities.

References​

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