The /responses proxy endpoint only required authentication via
get_verified_user but did not check per-model access grants. This
allowed any authenticated user to access any model through this
endpoint, bypassing the access control system.
Extract a shared check_model_access helper into utils/access_control
and replace all inline access control blocks across openai.py and
ollama.py (7 locations) with calls to this helper. This eliminates
code duplication and prevents future policy drift between endpoints.
CWE-862: Missing Authorization
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H (6.5 Medium)
The add_file_context function used a positional zip() to pair API
payload messages with DB-stored messages. After
process_messages_with_output() expands assistant messages containing
tool calls into multiple OpenAI-format messages (assistant + tool
results), the payload list becomes longer than the stored list. This
caused the zip to misalign, so subsequent user messages never received
their attached_files tags -- the model could see uploaded images via
vision but had no file URL to pass to edit_image.
Fix: filter both lists to user-role messages only before zipping.
User messages maintain the same order in both lists regardless of
assistant message expansion, restoring correct file context injection.
Fixes#21878