fix: escape ticket_id before interpolating into PostgREST filters in ai.py

CHANGELOG.md

@@ -10,6 +10,7 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ### Fixed
 - `db_patch`, `db_delete`, and the `{id}`-based ticket routes (`GET /tickets/{id}`, `GET /tickets/{id}/notes`, `GET /tickets/{id}/history`, and the status lookup in `PUT /tickets/{id}`) now escape the `id` path parameter before interpolating it into PostgREST filters, so a crafted id can no longer append extra conditions or query parameters.
 - `GET /tickets/search` and `GET /tickets/filter` no longer interpolate raw user input into PostgREST filter strings. Reserved logical-filter values are now quoted with embedded backslashes and quotes escaped, and all values are percent-encoded, so a crafted `q`, `status`, `priority`, or `assigned_user_id` can no longer break out of the intended filter or inject extra query parameters.
+- `POST /ai/suggest` no longer interpolates the caller-supplied `ticket_id` directly into PostgREST filters when loading the ticket and its notes. This was the same filter-injection gap already closed for the REST routes in `main.py`, but `ai.py`'s helpers were missed; they now escape `ticket_id` via `escape_filter_value` as well.
 
 ### Planned
 - Role-based auth (agent / lead / admin) with JWT bearer tokens

backend/ai.py

@@ -8,7 +8,7 @@
 from anthropic import Anthropic
 from dotenv import load_dotenv
 
-from database import db_get
+from database import db_get, escape_filter_value
 
 load_dotenv()
 
@@ -28,14 +28,16 @@ def _get_client() -> Anthropic:
 
 
 def _fetch_ticket(ticket_id: str) -> dict[str, Any]:
-    result = db_get("tickets", f"id=eq.{ticket_id}")
+    result = db_get("tickets", f"id=eq.{escape_filter_value(ticket_id)}")
     if not isinstance(result, list) or not result:
         raise ValueError(f"Ticket {ticket_id} not found")
     return result[0]
 
 
 def _fetch_notes(ticket_id: str) -> list[dict[str, Any]]:
-    notes = db_get("ticket_notes", f"ticket_id=eq.{ticket_id}&order=created_at.asc")
+    notes = db_get(
+        "ticket_notes", f"ticket_id=eq.{escape_filter_value(ticket_id)}&order=created_at.asc"
+    )
     return notes if isinstance(notes, list) else []
 
 

backend/test_ai.py

@@ -0,0 +1,52 @@
+from unittest.mock import MagicMock
+
+import pytest
+
+import ai
+import database
+
+# ---------------------------------------------------------------------------
+# _fetch_ticket / _fetch_notes -- ticket_id is escaped before interpolation
+#
+# POST /ai/suggest passes the caller-supplied ticket_id straight into these
+# helpers. Without escaping, a value such as "t1&status=eq.Closed" could
+# inject extra PostgREST query parameters, the same filter-injection class
+# fixed for the /tickets/search and /tickets/filter endpoints in main.py.
+# ---------------------------------------------------------------------------
+
+
+@pytest.fixture
+def fake_request(monkeypatch):
+    monkeypatch.setattr(database, "SUPABASE_URL", "https://example.supabase.co")
+    monkeypatch.setattr(database, "SUPABASE_KEY", "secret")
+    response = MagicMock()
+    response.status_code = 200
+    response.text = "[]"
+    response.json.return_value = []
+    request = MagicMock(return_value=response)
+    monkeypatch.setattr(database.requests, "request", request)
+    return request
+
+
+def test_fetch_ticket_escapes_injected_query_params(fake_request):
+    malicious_id = "t1&status=eq.Closed"
+
+    with pytest.raises(ValueError, match="not found"):
+        ai._fetch_ticket(malicious_id)
+
+    url = fake_request.call_args.args[1]
+    assert url.count("&") == 0, url
+    assert "status=eq.Closed" not in url
+    assert url.endswith("/rest/v1/tickets?id=eq." + database.escape_filter_value(malicious_id))
+
+
+def test_fetch_notes_escapes_injected_query_params(fake_request):
+    malicious_id = "t1&select=*"
+
+    notes = ai._fetch_notes(malicious_id)
+
+    assert notes == []
+    url = fake_request.call_args.args[1]
+    assert url.count("&") == 1, url  # only the legitimate trailing &order=... remains
+    assert "select=" not in url
+    assert "ticket_id=eq." + database.escape_filter_value(malicious_id) in url