The embedded workspace terminal spawns a PTY shell that runs arbitrary
commands as the server-process user. check_auth() returns True
unconditionally when no password/passkey is configured (the default
out-of-the-box state), so without a network-scope gate the terminal
endpoints were reachable by any unauthenticated caller able to hit the
port — which on a passwordless public bind is remote code execution.
Apply the same local-origin gate the onboarding/bootstrap endpoints use
(_onboarding_gate_allows) to /api/terminal/{start,input,resize,close} and
/api/terminal/output: with auth disabled, accept only loopback/private
origins, ignore spoofable X-Forwarded-For/X-Real-IP unless
HERMES_WEBUI_TRUST_FORWARDED_FOR=1, and honor HERMES_WEBUI_ONBOARDING_OPEN=1
as the explicit opt-out for a deliberately-exposed server. Auth-enabled
servers (cookie already verified upstream) and genuine same-host clients
are unaffected.
Also fixes a latent test-isolation leak in
test_extension_route_remains_behind_webui_auth: it set HERMES_WEBUI_PASSWORD
but never invalidated the process-wide password-hash cache, so its result
depended on suite execution order (exposed when the new test file shifted
ordering). Invalidate before+after so it reads the env var deterministically.
12 new gate tests in tests/test_cvd3_terminal_local_origin_gate.py.