has_access_to_file granted access whenever the file was attached to a
shared chat the user could read, ignoring the requested access_type. A
read-only shared-chat recipient therefore satisfied write and delete
checks and could delete or mutate the chat owner's attached file. Gate
the shared-chat branch on read access, matching the channels branch
directly above it.
Co-authored-by: oxsignal <oxsignal@users.noreply.github.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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)
