🛡️ Sentinel: [MEDIUM] Fix exception handling information leak in admin login

.jules/sentinel.md

@@ -21,3 +21,15 @@ Hardcoded credentials pose a critical risk because they provide an easy entry po
 **Prevention:**
 1. Never commit secrets, API keys, or passwords into the source code repository. Always read sensitive configuration using environment variables (e.g., `os.getenv`).
 2. Implement secure comparisons utilizing functions designed to prevent timing attacks, like `secrets.compare_digest()`, and properly encode inputs to prevent TypeErrors on non-ASCII characters.
+
+## 2024-05-20 - Exception Handling Information Leak in Admin Login
+
+**Vulnerability:**
+The `admin_login` route in `main.py` had a generic `except Exception as e:` block that caught all exceptions and returned the exception's string representation `str(e)` to the client inside a 401 Unauthorized response. If an unexpected internal error occurred (e.g. database failure, missing environment variables leading to a 500 error in `authenticate_admin`), the underlying error details or stack trace fragments could be exposed to potential attackers.
+
+**Learning:**
+Generic exception handlers that echo the error message back to the client violate the "fail securely" principle and create an Information Exposure vulnerability. Additionally, catching `Exception` indiscriminately in FastAPI can swallow intended `HTTPException` raises (like a 500 from misconfigured credentials), incorrectly returning them as 401s with leaked details.
+
+**Prevention:**
+1. Explicitly catch known HTTPExceptions and re-raise them, or handle them appropriately.
+2. Catch general `Exception` separately as a fallback and return generic, non-descriptive error messages to the client (e.g., "Internal server error") while logging the actual `str(e)` server-side.

main.py

@@ -92,9 +92,12 @@ async def admin_login(login_request: models.LoginRequest, response: Response):
         sessions[session_id] = login_request.username  # Map session ID to username
         response.set_cookie("session_id", session_id, httponly=True)
         return {"message": "Login successful"}
+    except HTTPException as e:
+        logging.error(f"Login failed for {login_request.username}: {str(e.detail)}")
+        raise e
     except Exception as e:
         logging.error(f"Login failed for {login_request.username}: {str(e)}")
-        raise HTTPException(status_code=401, detail=str(e))  # Unauthorized
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 # Admin logout route
 @app.post("/admin/logout/")