Open WebUI: Cross-user file disclosure via /api/chat/completions image_url field
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, POST /api/chat/completions accepts an image_url.url value that, when it does NOT start with http://, https://, or data:image/, is interpreted as a file id and resolved against the global file table with no ownership check. an authenticated user can therefore set image_url.url to another user's file id, the server reads that file from disk, base64-encodes it, and injects the data URI into the LLM request. the user then prompts the LLM to describe / OCR the file and reads the content back. This vulnerability is fixed in 0.9.6.
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-639 | CWE-639: Authorization Bypass Through User-Controlled Key |
Type: CWE
Description: CWE-639: Authorization Bypass Through User-Controlled Key
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 3.1 | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
Version: 3.1
Base score: 6.5
Base severity: MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N