execute_api_call — reachable by the LLM through the api_call agent
tool — joined the integration's user-configured base_url with an
LLM-controlled path and requested it with no IP validation, so a
base_url (or a hostname resolving) into the metadata range
(169.254.169.254) was fetched server-side with the integration's auth
headers attached.
Run check_outbound_url on the joined URL before connecting, matching
the gallery endpoint, embeddings, CardDAV, and reminder webhook
surfaces. Link-local/metadata is always rejected;
INTEGRATION_API_BLOCK_PRIVATE_IPS=true also blocks RFC-1918/loopback.
Private stays allowed by default because LAN integrations
(Home Assistant, Miniflux, ntfy) are the primary use case.
The truncation-test helpers stub the guard open because their
api.example.com fixture host does not resolve and the guard fails
closed on DNS errors.
Fixes#5143
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Wes Huber