chore(proxy): also scrub pass_through_endpoints[].target from DB overlay

A pass-through endpoint's ``target`` field is passed through
``create_pass_through_route`` into ``get_instance_fn`` during config
load. A PROXY_ADMIN persisting ``target: "s3://attacker/m.i"`` via
the DB-overlay ``pass_through_endpoints`` write path was not covered
by the previous scrub matrix, so the remote module load would still
reach the loader because the YAML-load chain has ``config_file_path``
set.

Walk each entry in ``general_settings.pass_through_endpoints`` and
null out any ``target`` that starts with ``s3://`` or ``gcs://``. The
entry itself is preserved so the path-registration helper can choose
how to handle a missing target (the existing code skips the route
when ``target is None``).

Adds two regression tests.

litellm/proxy/proxy_server.py

@@ -3203,6 +3203,25 @@ def _scrub_db_overlay_remote_module_loads(section: str, db_value: Any) -> Any:
                 jwt.get("custom_validate"),
             )
             jwt["custom_validate"] = None
+        # ``pass_through_endpoints`` is a list of dicts whose ``target``
+        # is passed through ``create_pass_through_route`` →
+        # ``get_instance_fn``. A DB-overlay ``target: "s3://attacker/m.i"``
+        # would otherwise reach the loader because the YAML-load chain
+        # has ``config_file_path`` set.
+        pte = sanitized.get("pass_through_endpoints")
+        if isinstance(pte, list):
+            for entry in pte:
+                if isinstance(entry, dict) and _is_remote_module_url(
+                    entry.get("target")
+                ):
+                    verbose_proxy_logger.warning(
+                        "Refused remote-URL target from DB-overlay "
+                        "general_settings.pass_through_endpoints "
+                        "(path=%r): %r",
+                        entry.get("path"),
+                        entry.get("target"),
+                    )
+                    entry["target"] = None
     return sanitized
 
 

tests/test_litellm/proxy/types_utils/test_db_overlay_remote_module_scrub.py

@@ -71,6 +71,35 @@ def test_custom_provider_map_custom_handler_stripped():
     assert cleaned["custom_provider_map"][1]["custom_handler"] is None
 
 
+def test_pass_through_endpoints_target_stripped():
+    overlay = {
+        "pass_through_endpoints": [
+            {"path": "/ok", "target": "my_module.legit_handler"},
+            {"path": "/bad-s3", "target": "s3://attacker/m.handler"},
+            {"path": "/bad-gcs", "target": "gcs://attacker/m.handler"},
+        ]
+    }
+    cleaned = _scrub_db_overlay_remote_module_loads("general_settings", overlay)
+    # Legit dotted-name target preserved
+    assert cleaned["pass_through_endpoints"][0]["target"] == "my_module.legit_handler"
+    # Both remote URLs stripped to None — entry remains so the path
+    # registration can still be skipped explicitly downstream
+    assert cleaned["pass_through_endpoints"][1]["target"] is None
+    assert cleaned["pass_through_endpoints"][2]["target"] is None
+    # Sibling fields preserved
+    assert cleaned["pass_through_endpoints"][0]["path"] == "/ok"
+    assert cleaned["pass_through_endpoints"][1]["path"] == "/bad-s3"
+
+
+def test_pass_through_endpoints_non_list_passthrough():
+    # If pass_through_endpoints is mistyped (not a list), the scrub
+    # must not raise.
+    cleaned = _scrub_db_overlay_remote_module_loads(
+        "general_settings", {"pass_through_endpoints": "not-a-list"}
+    )
+    assert cleaned["pass_through_endpoints"] == "not-a-list"
+
+
 def test_litellm_jwtauth_custom_validate_stripped():
     overlay = {
         "litellm_jwtauth": {