Improper Input Validation

Summary

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to version 39.8.6, 40.x prior to 40.9.0, 41.x prior to 41.1.1 and 42.x prior to 42.0.0-beta.1, `shell.openPath()` did not reject paths containing embedded null bytes. Apps that perform string-only validation of file paths, for example checking the file extension, before passing them to `shell.openPath()` could be bypassed, allowing an attacker-controlled path to open a different file than the one that passed validation. Apps are only affected if they pass paths derived from untrusted input to `shell.openPath()` and rely on string-based validation without a filesystem check. This issue is fixed in versions 39.8.6, 40.9.0, 41.1.1, and 42.0.0-beta.1.