fix(webui): refuse to expose training controls without auth

README.md

@@ -97,7 +97,8 @@ python -m skillopt_webui.app
 | `--host` | `127.0.0.1` | Bind address |
 | `--share` | off | Create a public Gradio share link |
 
-The default host is loopback-only; pass `--host 0.0.0.0` to expose the dashboard.
+The default host is loopback-only. Exposing the dashboard (`--host 0.0.0.0` or `--share`) requires
+`--auth-user`/`--auth-pass` (or `SKILLOPT_WEBUI_USER`/`SKILLOPT_WEBUI_PASS`).
 
 ---
 

docs/guide/first-experiment.md

@@ -127,8 +127,8 @@ python -m skillopt_webui.app
 ```
 
 Then open `http://localhost:7860` in your browser to configure parameters and
-launch training. The default host is `0.0.0.0`; pass `--host 127.0.0.1` for a
-local-only dashboard.
+launch training. The default host is `127.0.0.1`; exposing it with `--host 0.0.0.0`
+requires `--auth-user`/`--auth-pass`.
 
 ## Next Steps
 

docs/reference/cli.md

@@ -447,4 +447,5 @@ python -m skillopt_webui.app [--port PORT] [--share]
 | `--host` | `127.0.0.1` | Server bind address |
 | `--share` | false | Create public Gradio link |
 
-The default host binds loopback only; pass `--host 0.0.0.0` to expose the dashboard.
+The default host binds loopback only. Exposing the dashboard (`--host 0.0.0.0` or `--share`) requires
+`--auth-user`/`--auth-pass` (or `SKILLOPT_WEBUI_USER`/`SKILLOPT_WEBUI_PASS`).

skillopt_webui/app.py

@@ -760,12 +760,16 @@ def main():
     parser.add_argument("--port", type=int, default=7860)
     parser.add_argument("--share", action="store_true")
     parser.add_argument("--host", type=str, default="127.0.0.1",
-                        help="Server host. Default is localhost; use 0.0.0.0 "
-                             "to expose publicly (no auth, use with care).")
+                        help="Server host. Default is localhost; binding any "
+                             "other address requires --auth-user/--auth-pass.")
     parser.add_argument("--auth-user", type=str, default=None,
                         help="Username for basic auth (or set SKILLOPT_WEBUI_USER).")
     parser.add_argument("--auth-pass", type=str, default=None,
                         help="Password for basic auth (or set SKILLOPT_WEBUI_PASS).")
+    parser.add_argument("--allow-unauthenticated", action="store_true",
+                        help="Allow --share or a non-loopback --host without "
+                             "auth. Anyone who can reach the UI can then launch "
+                             "training jobs with your API keys.")
     args = parser.parse_args()
 
     if args.host and args.host not in ("127.0.0.1", "localhost", "::1"):
@@ -803,6 +807,19 @@ def main():
         )
         sys.exit(1)
 
+    # The training controls launch jobs with the API keys from .env and
+    # .secrets/, so never expose them beyond loopback without login unless
+    # the operator explicitly opts in.
+    exposed = args.share or args.host not in ("127.0.0.1", "localhost", "::1")
+    if exposed and not auth and not args.allow_unauthenticated:
+        print(
+            "Refusing to start: --share / a non-loopback --host requires "
+            "--auth-user and --auth-pass (or SKILLOPT_WEBUI_USER and "
+            "SKILLOPT_WEBUI_PASS). Pass --allow-unauthenticated to override.",
+            file=sys.stderr,
+        )
+        sys.exit(1)
+
     app = build_ui()
     launch_kwargs = build_launch_kwargs(args.host, args.port, args.share)
     if auth:

tests/test_webui_security.py

@@ -48,7 +48,7 @@ def test_main_warns_on_public_host(webui, monkeypatch, capsys):
     app_mock = mock.MagicMock()
     app_mock.launch = launcher
     monkeypatch.setattr(webui_mod, "build_ui", lambda: app_mock)
-    monkeypatch.setattr(sys, "argv", ["app.py", "--host", "0.0.0.0"])
+    monkeypatch.setattr(sys, "argv", ["app.py", "--host", "0.0.0.0", "--allow-unauthenticated"])
 
     webui_mod.main()
 
@@ -65,7 +65,7 @@ def test_main_warns_on_share(webui, monkeypatch, capsys):
     app_mock = mock.MagicMock()
     app_mock.launch = launcher
     monkeypatch.setattr(webui_mod, "build_ui", lambda: app_mock)
-    monkeypatch.setattr(sys, "argv", ["app.py", "--share"])
+    monkeypatch.setattr(sys, "argv", ["app.py", "--share", "--allow-unauthenticated"])
 
     webui_mod.main()
 
@@ -74,6 +74,40 @@ def test_main_warns_on_share(webui, monkeypatch, capsys):
     assert "public" in captured.err.lower() or "tunnel" in captured.err.lower()
 
 
+@pytest.mark.parametrize("argv", [["--host", "0.0.0.0"], ["--share"]])
+def test_main_refuses_exposed_without_auth(webui, monkeypatch, argv):
+    """A public bind or share link without auth must fail closed (never launch)."""
+    webui_mod = webui
+    launcher = mock.MagicMock()
+    app_mock = mock.MagicMock()
+    app_mock.launch = launcher
+    monkeypatch.setattr(webui_mod, "build_ui", lambda: app_mock)
+    monkeypatch.setattr(sys, "argv", ["app.py", *argv])
+    monkeypatch.delenv("SKILLOPT_WEBUI_USER", raising=False)
+    monkeypatch.delenv("SKILLOPT_WEBUI_PASS", raising=False)
+    with pytest.raises(SystemExit):
+        webui_mod.main()
+    launcher.assert_not_called()
+
+
+def test_main_allows_exposed_with_auth(webui, monkeypatch):
+    """A public bind with auth configured must launch with that auth."""
+    webui_mod = webui
+    launcher = mock.MagicMock()
+    app_mock = mock.MagicMock()
+    app_mock.launch = launcher
+    monkeypatch.setattr(webui_mod, "build_ui", lambda: app_mock)
+    monkeypatch.setattr(
+        sys, "argv", ["app.py", "--host", "0.0.0.0", "--auth-user", "admin", "--auth-pass", "s3cret"]
+    )
+
+    webui_mod.main()
+
+    _args, kwargs = launcher.call_args
+    assert kwargs["server_name"] == "0.0.0.0"
+    assert kwargs.get("auth") == ("admin", "s3cret")
+
+
 def test_main_auth_via_cli_args(webui, monkeypatch):
     """--auth-user and --auth-pass must enable Gradio basic auth."""
     webui_mod = webui