Open WebUI: SSRF Bypass via HTTP Redirect Following in Web-Fetch and Image-Load Endpoints
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, the validate_url() function in backend/open_webui/retrieval/web/utils.py only validates the initial URL submitted by the caller. The HTTP clients used downstream (sync requests, async aiohttp, langchain's WebBaseLoader) follow HTTP 3xx redirects by default and do not re-validate the redirect target against the private-IP / metadata-IP block list. Any authenticated user can therefore submit a public URL that 302-redirects to an internal address (e.g. 127.0.0.1, 169.254.169.254, RFC1918) and read the internal response body via the /api/v1/retrieval/process/web endpoint, the /api/v1/images/... endpoints, the /api/chat/completions endpoint with an image_url content part, and any other route that calls these helpers. This vulnerability is fixed in 0.9.5.
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-918 | CWE-918: Server-Side Request Forgery (SSRF) |
Type: CWE
Description: CWE-918: Server-Side Request Forgery (SSRF)
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 3.1 | 8.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N |
Version: 3.1
Base score: 8.5
Base severity: HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N