GHSA-29vq-49wr-vm6x
Werkzeug safe_join() allows Windows special device names
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
Werkzeug's `safe_join` function allows Windows device names as filenames if when preceded by other path segments.
This was previously reported as https://github.com/pallets/werkzeug/security/advisories/GHSA-hgf8-39gv-g3f2, but the added filtering failed to account for the fact that `safe_join` accepts paths with multiple segments, such as `example/NUL`.
`send_from_directory` uses `safe_join` to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely.
References
External links from the advisory. They lead to third-party sites.