A XSS vulnerability exists on index pages for static file handling.
When using web.static(..., show_index=True)
, the resulting index pages do not escape file names.
If users can upload files with arbitrary filenames to the static directory, the server is vulnerable to XSS attacks.
We have always recommended using a reverse proxy server (e.g. nginx) for serving static files. Users following the recommendation are unaffected.
Other users can disable show_index
if unable to upgrade.
Patch: https://github.com/aio-libs/aiohttp/pull/8319/files