fix: hardened security, CSP enforcement, SSRF redirect validation, reenabled S/MIME chain verify, IP spoofing prevention, PDF iframe sandbox

app/[locale]/files/page.tsx

@@ -17,15 +17,18 @@ import { SidebarAppsModal } from "@/components/layout/sidebar-apps-modal";
 import { InlineAppView } from "@/components/layout/inline-app-view";
 import { useSidebarApps } from "@/hooks/use-sidebar-apps";
 import { useIsMobile } from "@/hooks/use-media-query";
+import { usePolicyStore } from "@/stores/policy-store";
 import { FileBrowser } from "@/components/files/file-browser";
 import { ImagePreviewModal } from "@/components/files/image-preview-modal";
 import { FilePreviewModal } from "@/components/files/file-preview-modal";
 import { loadFilesSettings } from "@/components/files/files-settings-dialog";
 import type { FolderLayout } from "@/components/files/files-settings-dialog";
+import { AlertTriangle } from "lucide-react";
 
 export default function FilesPage() {
   const router = useRouter();
   const t = useTranslations("files");
+  const filesEnabled = usePolicyStore((s) => s.isFeatureEnabled('filesEnabled'));
   const { isAuthenticated, logout, checkAuth, isLoading: authLoading, client } = useAuthStore();
   const { showAppsModal, inlineApp, loadedApps, handleManageApps, handleInlineApp, closeInlineApp, closeAppsModal } = useSidebarApps();
   const [initialCheckDone, setInitialCheckDone] = useState(() => useAuthStore.getState().isAuthenticated && !!useAuthStore.getState().client);
@@ -393,7 +396,15 @@ export default function FilesPage() {
             )}
 
             <div className="flex-1 min-h-0">
-              {supportsFiles === false ? (
+              {!filesEnabled ? (
+                <div className="flex items-center justify-center h-full">
+                  <div className="max-w-lg text-center space-y-3 px-4">
+                    <AlertTriangle className="w-10 h-10 text-yellow-500 mx-auto" />
+                    <p className="text-sm font-medium">Files feature is disabled by your administrator</p>
+                    <p className="text-xs text-muted-foreground">Large file uploads via WebDAV can cause Stalwart/RocksDB instability, including out-of-memory crashes and unrecoverable disk usage. Deleted files may not be immediately purged from blob storage. This feature is not recommended for production environments.</p>
+                  </div>
+                </div>
+              ) : supportsFiles === false ? (
                 <div className="flex items-center justify-center h-full">
                   <p className="text-sm text-muted-foreground">{t("not_available")}</p>
                 </div>

app/admin/policy/page.tsx

@@ -19,6 +19,7 @@ const FEATURE_GATE_LABELS: Partial<Record<keyof FeatureGates, { label: string; d
   debugModeEnabled: { label: 'Debug Mode', description: 'Allow users to enable debug/diagnostic mode' },
   folderIconsEnabled: { label: 'Folder Icons', description: 'Allow custom folder icon picker' },
   hoverActionsConfigEnabled: { label: 'Hover Actions Config', description: 'Allow users to customize email hover actions' },
+  filesEnabled: { label: 'Files (WebDAV)', description: 'Enable file storage via WebDAV. WARNING: Large uploads can cause Stalwart/RocksDB instability. Not recommended for production.' },
 };
 
 const RESTRICTABLE_SETTINGS = [

app/api/fetch-ical/route.ts

@@ -64,20 +64,43 @@ export async function POST(request: NextRequest) {
     const controller = new AbortController();
     const timeout = setTimeout(() => controller.abort(), FETCH_TIMEOUT_MS);
 
-    const response = await fetch(url, {
-      signal: controller.signal,
-      headers: {
-        'Accept': 'text/calendar, application/ics, text/plain, */*',
-        'User-Agent': 'JMAP-Webmail/1.0 Calendar-Fetcher',
-      },
-      redirect: 'follow',
-    });
+    const MAX_REDIRECTS = 5;
+    let currentUrl = url;
+    let response: Response | undefined;
+
+    for (let i = 0; i <= MAX_REDIRECTS; i++) {
+      if (!isValidExternalUrl(currentUrl)) {
+        clearTimeout(timeout);
+        return NextResponse.json({ error: 'Redirect to disallowed URL' }, { status: 400 });
+      }
+
+      response = await fetch(currentUrl, {
+        signal: controller.signal,
+        headers: {
+          'Accept': 'text/calendar, application/ics, text/plain, */*',
+          'User-Agent': 'JMAP-Webmail/1.0 Calendar-Fetcher',
+        },
+        redirect: 'manual',
+      });
+
+      if (response.status >= 300 && response.status < 400) {
+        const location = response.headers.get('location');
+        if (!location) {
+          clearTimeout(timeout);
+          return NextResponse.json({ error: 'Redirect without Location header' }, { status: 502 });
+        }
+        // Resolve relative redirects
+        currentUrl = new URL(location, currentUrl).toString();
+        continue;
+      }
+      break;
+    }
 
     clearTimeout(timeout);
 
-    if (!response.ok) {
+    if (!response || !response.ok) {
       return NextResponse.json(
-        { error: `Remote server returned ${response.status}` },
+        { error: `Remote server returned ${response?.status ?? 'unknown'}` },
         { status: 502 }
       );
     }