fix: validate Playwright navigations and gate redirects in web loader (#24756)

SafePlaywrightURLLoader validated only the initially submitted URL and
then let the browser follow HTTP redirects and client-side navigations
without re-checking them, so a public URL could redirect into the
internal network (cloud metadata, RFC1918, loopback). Intercept
document-type requests, re-run validate_url on each, and apply the same
redirect policy as the requests loader (blocked unless
AIOHTTP_CLIENT_ALLOW_REDIRECTS). Sub-resource requests pass through
unchanged so page rendering performance is unaffected.

Co-authored-by: POV9en <POV9en@users.noreply.github.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/open_webui/retrieval/web/utils.py

@@ -421,6 +421,62 @@ class SafePlaywrightURLLoader(PlaywrightURLLoader, RateLimitMixin, URLProcessing
         self.trust_env = trust_env
         self.playwright_timeout = playwright_timeout
 
+    def _intercept_navigation_sync(self, route, request=None):
+        req = request or route.request
+
+        if req.resource_type != 'document':
+            route.continue_()
+            return
+
+        try:
+            validate_url(req.url)
+        except Exception:
+            route.abort()
+            return
+
+        if AIOHTTP_CLIENT_ALLOW_REDIRECTS:
+            resp = route.fetch()
+        else:
+            try:
+                resp = route.fetch(max_redirects=0)
+            except TypeError:
+                route.abort()
+                return
+
+            if 300 <= resp.status < 400:
+                route.abort()
+                return
+
+        route.fulfill(response=resp)
+
+    async def _intercept_navigation(self, route, request=None):
+        req = request or route.request
+
+        if req.resource_type != 'document':
+            await route.continue_()
+            return
+
+        try:
+            await run_in_threadpool(validate_url, req.url)
+        except Exception:
+            await route.abort()
+            return
+
+        if AIOHTTP_CLIENT_ALLOW_REDIRECTS:
+            resp = await route.fetch()
+        else:
+            try:
+                resp = await route.fetch(max_redirects=0)
+            except TypeError:
+                await route.abort()
+                return
+
+            if 300 <= resp.status < 400:
+                await route.abort()
+                return
+
+        await route.fulfill(response=resp)
+
     def lazy_load(self) -> Iterator[Document]:
         """Safely load URLs synchronously with support for remote browser."""
         from playwright.sync_api import sync_playwright
@@ -436,6 +492,7 @@ class SafePlaywrightURLLoader(PlaywrightURLLoader, RateLimitMixin, URLProcessing
                 try:
                     self._safe_process_url_sync(url)
                     page = browser.new_page()
+                    page.route('**/*', self._intercept_navigation_sync)
                     response = page.goto(url, timeout=self.playwright_timeout)
                     if response is None:
                         raise ValueError(f'page.goto() returned None for url {url}')
@@ -465,6 +522,7 @@ class SafePlaywrightURLLoader(PlaywrightURLLoader, RateLimitMixin, URLProcessing
                 try:
                     await self._safe_process_url(url)
                     page = await browser.new_page()
+                    await page.route('**/*', self._intercept_navigation)
                     response = await page.goto(url, timeout=self.playwright_timeout)
                     if response is None:
                         raise ValueError(f'page.goto() returned None for url {url}')