Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.6, 40.9.0, 41.1.1, and 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.

Affected: npm: electron

### Impact `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. Node's `fs` APIs already reject paths containing null bytes, so apps that call `fs.existsSync()`, `fs.stat()`, or similar before `shell.openPath()` are not affected. Apps that do not call `shell.openPath()` with untrusted input are not affected.

### Workarounds Reject any path containing a null byte before passing it to `shell.openPath()`: ```js if (filePath.includes('\0')) throw new Error('invalid path'); ```

### Fixed Versions * `42.0.0-beta.1` * `41.1.1` * `40.9.0` * `39.8.6`

### For more information If you have any questions or comments about this advisory, email us at [security@electronjs.org](mailto:security@electronjs.org)