Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, the audio transcription upload endpoint takes the file extension from the user-supplied filename and saves the file under CACHE_DIR/audio/transcriptions/.. The /cache/{path} route serves these files via FileResponse, which sets Content-Type from the on-disk extension and emits no Content-Disposition. A verified user with the default-on chat.stt permission can upload a polyglot WAV+HTML file named pwn.html and trick any other user into opening the resulting URL — the response comes back as text/html and any embedded <script> runs in the Open WebUI origin. This vulnerability is fixed in 0.9.3.
Problem types
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-434: Unrestricted Upload of File with Dangerous Type
CWE-646: Reliance on File Name or Extension of Externally-Supplied File
Product status
References
github.com/...-webui/security/advisories/GHSA-m8f9-9whg-f4xr
github.com/...-webui/security/advisories/GHSA-m8f9-9whg-f4xr