fix: security file upload (langflow-ai#3923)

* fix: add check user authentication
* fix: add request body multipart boundary validation

.gitignore

@@ -273,3 +273,5 @@ src/frontend/temp
 *-shm
 *-wal
 .history
+
+.dspy_cache/

src/backend/base/langflow/api/v1/files.py

@@ -40,6 +40,8 @@ def get_flow_id(
 async def upload_file(
     file: UploadFile,
     flow_id: UUID = Depends(get_flow_id),
+    current_user=Depends(get_current_active_user),
+    session=Depends(get_session),
     storage_service: StorageService = Depends(get_storage_service),
 ):
     try:
@@ -50,6 +52,10 @@ async def upload_file(
             )
 
         flow_id_str = str(flow_id)
+        flow = session.get(Flow, flow_id_str)
+        if flow.user_id != current_user.id:
+            raise HTTPException(status_code=403, detail="You don't have access to this flow")
+
         file_content = await file.read()
         timestamp = datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
         file_name = file.filename or hashlib.sha256(file_content).hexdigest()

src/backend/base/langflow/main.py

@@ -1,14 +1,15 @@
 import asyncio
 import json
 import os
+import re
 import warnings
 from contextlib import asynccontextmanager
 from http import HTTPStatus
 from pathlib import Path
 from urllib.parse import urlencode
 
 import nest_asyncio  # type: ignore
-from fastapi import FastAPI, HTTPException, Request, Response
+from fastapi import FastAPI, HTTPException, Request, Response, status
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import FileResponse, JSONResponse
 from fastapi.staticfiles import StaticFiles
@@ -127,6 +128,39 @@ def create_app():
     )
     app.add_middleware(JavaScriptMIMETypeMiddleware)
 
+    @app.middleware("http")
+    async def check_boundary(request: Request, call_next):
+        if "/api/v1/files/upload" in request.url.path:
+            content_type = request.headers.get("Content-Type")
+
+            if not content_type or "multipart/form-data" not in content_type or "boundary=" not in content_type:
+                return JSONResponse(
+                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                    content={"detail": "Content-Type header must be 'multipart/form-data' with a boundary parameter."},
+                )
+
+            boundary = content_type.split("boundary=")[-1].strip()
+
+            if not re.match(r"^[\w\-]{1,70}$", boundary):
+                return JSONResponse(
+                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                    content={"detail": "Invalid boundary format"},
+                )
+
+            body = await request.body()
+
+            boundary_start = f"--{boundary}".encode()
+            boundary_end = f"--{boundary}--\r\n".encode()
+
+            if not body.startswith(boundary_start) or not body.endswith(boundary_end):
+                return JSONResponse(
+                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                    content={"detail": "Invalid multipart formatting"},
+                )
+
+        response = await call_next(request)
+        return response
+
     @app.middleware("http")
     async def flatten_query_string_lists(request: Request, call_next):
         flattened: list[tuple[str, str]] = []

src/frontend/tests/core/unit/tableInputComponent.spec.ts

@@ -123,7 +123,7 @@ class CustomComponent(Component):
   ];
 
   for (const text of allVisibleTexts) {
-    await expect(page.getByText(text)).toBeVisible();
+    await expect(page.getByText(text).last()).toBeVisible();
   }
 
   await page.locator(".ag-cell-value").first().click();