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Lack of isolation methods

Need​

Implementation of isolation methods for running applications

Context​

  • Usage of Swift for iOS and macOS app development
  • Usage of UIKit for building modern and responsive user interfaces

Description​

Non compliant code​

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        let app = UIApplication.shared
        let url = URL(string: "https://www.example.com")!
        app.open(url)
    }
}

The above Swift code represents a ViewController in an iOS application, where an external URL is opened directly within the application's main process.

This code is vulnerable due to the lack of isolation methods. It directly opens a URL within the application's main process without any isolation, which could lead to potential security risks. If the URL is compromised, it can directly affect the application's process, leading to potential data leaks or malicious actions.

The vulnerability lies in the app.open(url) line, where the application opens a URL without any isolation or sandboxing. This means that any scripts or actions on the opened URL have direct access to the application's main process. This lack of isolation could potentially allow a malicious URL to perform unwanted actions within the application, such as accessing sensitive data or performing unwanted actions.

The recommended fix for this vulnerability would be to implement isolation methods, such as running the URL in a separate process or a sandboxed environment, to prevent potential security risks. This would ensure that any potential malicious actions from the URL would not directly affect the application's main process.

Steps​

  • Implement proper sandboxing to isolate the application from other processes and resources.
  • Use secure communication protocols (e.g., HTTPS) to ensure data privacy and integrity.
  • Implement access controls and permissions to restrict the application's access to sensitive resources.
  • Apply the principle of least privilege, granting the application only the necessary permissions to perform its intended functionality.
  • Regularly update and patch the application to address any known vulnerabilities and security issues.
  • Implement secure coding practices to prevent common security vulnerabilities, such as input validation and output encoding.
  • Conduct regular security assessments and penetration testing to identify and address any potential vulnerabilities.
  • Educate developers and users about secure coding practices and the importance of maintaining a secure application environment.

Compliant code​

import UIKit
import SafariServices

class ViewController: UIViewController, SFSafariViewControllerDelegate {
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        let url = URL(string: "https://www.example.com")!
        let safariVC = SFSafariViewController(url: url)
        safariVC.delegate = self
        self.present(safariVC, animated: true, completion: nil)
    }
    
    func safariViewControllerDidFinish(_ controller: SFSafariViewController) {
        controller.dismiss(animated: true, completion: nil)
    }
}

The updated code now uses the SFSafariViewController to open the URL. This is a more secure way to open URLs as it provides isolation between the host app and the web content. The SFSafariViewController runs in a separate process and not in the app's process, providing an additional layer of security.

The SFSafariViewController also includes Safari features such as Reader, AutoFill, Fraudulent Website Detection, and content blocking. It shares cookies and other website data with Safari, and has the same permissions as Safari—like camera, location, and microphone access.

The safariViewControllerDidFinish function is a delegate method that gets called when the user decides to close the Safari View Controller. This allows the app to perform any necessary cleanup or follow-up actions.

This approach provides a more secure way to open URLs, isolating the app from the web content, and providing a consistent and familiar user experience.

References​

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