Electron subject to Exfiltration of hashed SMB credentials on Windows via file:// redirect

Vulnerability Description

The Electron framework enables writing cross-platform desktop applications using JavaScript, HTML and CSS. In versions prior to 21.0.0-beta.1, 20.0.1, 19.0.11, and 18.3.7, Electron is vulnerable to Exposure of Sensitive Information. When following a redirect, Electron delays a check for redirecting to file:// URLs from other schemes. The contents of the file is not available to the renderer following the redirect, but if the redirect target is a SMB URL such as `file://some.website.com/`, then in some cases, Windows will connect to that server and attempt NTLM authentication, which can include sending hashed credentials.This issue has been patched in versions: 21.0.0-beta.1, 20.0.1, 19.0.11, and 18.3.7. Users are recommended to upgrade to the latest stable version of Electron. If upgrading isn't possible, this issue can be addressed without upgrading by preventing redirects to file:// URLs in the `WebContents.on('will-redirect')` event, for all WebContents as a workaround.

References

• https://github.com/electron/electron/security/advisories/GHSA-p2jh-44qj-pf2v