Gatsby is a free and open source framework based on React. The Gatsby framework prior to versions 4.25.7 and 5.9.1 contain a Local File Inclusion vulnerability in the `__file-code-frame` and `__original-stack-frame` paths, exposed when running the Gatsby develop server (`gatsby develop`). Any file in scope of the development server could potentially be exposed. It should be noted that by default `gatsby develop` is only accessible via the localhost `127.0.0.1`, and one would need to intentionally expose the server to other interfaces to exploit this vulnerability by using server options such as `--host 0.0.0.0`, `-H 0.0.0.0`, or the `GATSBY_HOST=0.0.0.0` environment variable. A patch has been introduced in `gatsby@5.9.1` and `gatsby@4.25.7` which mitigates the issue. Users are advised to upgrade. Users unable to upgrade should avoid exposing their development server to the internet.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.