Cline: Cross-Origin WebSocket Hijacking in Cline Hub Dashboard (`/browser` endpoint)

### Summary The Cline Hub dashboard server (`@cline/cline-hub`), launched via the `cline dashboard` CLI command, accepts WebSocket connections on the `/browser` endpoint without validating the HTTP `Origin` header. When `ROOM_SECRET` is not set—the default for local (`127.0.0.1`) binds—`isAuthorizedBrowserRequest()` returns `true` unconditionally, allowing any website a developer visits to open a cross-origin WebSocket to `ws://127.0.0.1:8787/browser`. An attacker-controlled page can then send `desktopCommand` frames to read workspace/session state, mutate MCP and provider settings, and—because dashboard sessions default to `autoApprove: true` for all tools—trigger arbitrary command execution when a provider/model is configured. Dynamically confirmed: an `upsert_mcp_server` frame injected a malicious `stdio` MCP server entry into the victim's Cline settings file with `ok: true` response. ### Details The vulnerable code path spans multiple files in the `apps/cline-hub` workspace. **No secret by default (local bind)** `apps/cline-hub/src/options.ts:54–57` converts an empty `ROOM_SECRET` environment variable to `undefined`: ```ts // apps/cline-hub/src/options.ts:54 function normalizeRoomSecret(value: string | undefined): string | undefined { const secret = value?.trim(); return secret ? secret : undefined; } ``` `apps/cline-hub/src/options.ts:67–85` allows the local default host (`127.0.0.1`) to start without a secret, so `roomSecret` remains `undefined` in the default configura