GHSA-9f4c-93c8-jc8g Electron: Sandboxed iframe can bypass the allow-popups restriction via the OpenURL navigation path

• npm electron: >= 42.0.0-alpha.1, < 42.0.1 → fixed in 42.0.1 • npm electron: >= 40.0.0-alpha.1, < 41.10.3 → fixed in 41.10.3 • npm electron: < 39.8.10 → fixed in 39.8.10

Impact A sandboxed iframe without the `allow-popups` keyword could still open a new window (or trigger `setWindowOpenHandler`) with no user interaction, because new-window navigations taking the OpenURL path did not apply the iframe sandbox popup restriction. Apps that embed untrusted content in sandboxed iframes and rely on the absence of `allow-popups` to prevent window creation are affected. Apps that deny window creation in `setWindowOpenHandler`, or that do not embed untrusted content in sandboxed iframes, are not affected. Workarounds Return `{ action: 'deny' }` from `setWindowOpenHandler` for any content you do not trust, rather than relying on the iframe sandbox alone. Fixed Versions • `42.0.1` • `41.10.3` • `39.8.10` For more information If you have any questions or comments about this advisory, email Electron at [email protected]