Open WebUI: SSRF into internal services via unvalidated sub-resource requests in the Playwright web loader

Summary

With the Playwright web loader enabled, Open WebUI opens user-submitted URLs in a real browser and validates the destination address before allowing the request. That check only ran for the top-level page request. Every other request the page issued was passed through unvalidated, so a page could use its own JavaScript to reach addresses the validation exists to block. Because the loader returns the page's final DOM to the requesting user, anything the page read back from those addresses ends up in the web-search or RAG output.

Preconditions

• WEB_LOADER_ENGINE=playwright. This is not the default; deployments on the default web loader are unaffected.
• A reachable Playwright browser, either local or via PLAYWRIGHT_WS_URL.
• Any authenticated user who can submit a URL for ingestion or trigger a web search. No administrator role is required.
• Something worth reading on a network the browser can reach. A deployment whose browser container has no route to internal services loses nothing here.

Impact

An authenticated user can read HTTP responses from services reachable by the browser process: cloud instance metadata, other containers on the same network, and internal APIs bound to private addresses. The content is returned to the user through the normal web-search or document-ingestion result, so this is a read primitive, not a blind one. It confers no write access and no availability impact, and it does not extend beyond what the browser's network position already allows.

Fix

Fixed in 0.11.0 by commit bef63a2ae. Every intercepted request is now validated, fetched with redirects disabled, re-validated on each redirect hop and then fulfilled, so neither a sub-resource nor a redirect can land on a non-global address. The same change blocks the two paths that never reached the interceptor at all: service-worker requests, via service_workers="block", and WebSocket connections, via a route handler that never connects upstream. Upgrading to 0.11.0 fully resolves the issue; no configuration change is required.