Open WebUI: Read-Only Users Can Toggle Note Pin Status via Incorrect Permission Check (Write via Read-Only Access)

Summary

The POST /api/v1/notes/{id}/pin endpoint performs a write operation (toggling the is_pinned field) but only checks for read permission. Users with read-only access to a shared note can pin/unpin it, which is a state-modifying action that should require write permission. All other write endpoints (update, delete, access/update) correctly check for write permission.

Details

Affected code: backend/open_webui/routers/notes.py lines 412-444

@router.post('/{id}/pin', response_model=Optional[NoteModel])
async def pin_note_by_id(...):
    # ...
    if user.role != 'admin' and (
        user.id != note.user_id
        and not await AccessGrants.has_access(
            user_id=user.id,
            resource_type='note',
            resource_id=note.id,
            permission='read',        # BUG: should be 'write'
            db=db,
        )
    ):
        raise HTTPException(...)
    
    note = await Notes.toggle_note_pinned_by_id(id, db=db)  # write operation

Compare with update endpoint (correct, line 318-327):

async def update_note_by_id(...):
    # ...
    and not await AccessGrants.has_access(
        permission='write',        # correctly checks 'write'
    )

PoC

Environment: Open WebUI v0.9.2, default configuration with notes sharing enabled.

Setup:

1. UserA creates a note
2. UserA shares note with UserB with read permission via POST /api/v1/notes/{id}/access/update with {"access_grants":[{"principal_type":"user","principal_id":"USERB_ID","permission":"read"}]}

Test: