CVE-2022-36077: Electron Framework Exposure of Sensitive Information via Redirects to file:// URLs

The Electron framework is a popular choice for developing cross-platform desktop applications using JavaScript, HTML, and CSS. It allows developers to create powerful applications with responsive user interfaces and seamless integration with the underlying operating system. However, despite its many benefits, a recently discovered vulnerability (CVE-2022-36077) in certain Electron versions may lead to the exposure of sensitive information.

Vulnerability Details

Electron is vulnerable to an Exposure of Sensitive Information issue in versions prior to 21..-beta.1, 20..1, 19..11, and 18.3.7. When following a redirect, Electron delays checking for redirects to file:// URLs from other schemes. While the contents of the target file are not disclosed to the renderer after the redirect, Windows may attempt NTLM authentication and send hashed credentials if the redirect target is an SMB URL such as file://some.website.com/.

Mitigation Steps

To address this vulnerability, Electron has released patched versions: 21..-beta.1, 20..1, 19..11, and 18.3.7. Users are advised to upgrade to the latest stable version of Electron to prevent potential risks associated with this vulnerability. If upgrading is not feasible, a workaround is available by preventing redirects to file:// URLs in the WebContents.on('will-redirect') event for all WebContents. Here's a code snippet demonstrating the workaround:

app.on('ready', () => {
  // Create a new browser window and load the application
  const mainWindow = new BrowserWindow();

  // Attach a 'will-redirect' event listener to the mainWindow.webContents
  mainWindow.webContents.on('will-redirect', (event, newUrl) => {
    // Check if the URL starts with 'file://' and prevent the redirect if it does
    if (newUrl.startsWith('file://')) {
      event.preventDefault();
    }
  });

  // Load the application URL
  mainWindow.loadURL('https://your-application-url.com';);
});

Original References

* Electron Release Notes
* CVE-2022-36077 - NIST National Vulnerability Database

Conclusion

Application security is paramount in the software development process, and staying up to date with the latest vulnerability disclosures and patches is crucial. As demonstrated with CVE-2022-36077 in the Electron framework, even widely-used platforms can occasionally contain vulnerabilities that expose sensitive information.

By upgrading to the latest stable version of Electron or implementing the suggested workaround, developers can ensure their applications are protected against this vulnerability. Be sure to monitor and follow up on any security updates and announcements to maintain a robust security posture for your application.

Timeline

Published on: 11/08/2022 07:15:00 UTC
Last modified on: 11/09/2022 19:16:00 UTC