Hug's minimalist philosophy often leads developers to neglect the production hardening phase. Defaulting to debug mode or permissive CORS headers turns an efficient API into an information disclosure goldmine. To secure Hug, we must kill the debug overhead and enforce a strict origin policy through the middleware stack.

The Vulnerable Pattern

import hug
@hug.get(‘/cmd’)
def exec_info():
return {‘internal_id’: 0xc0ffee}
VULNERABLE: Debug mode leaks stack traces and environment details
No CORS protection allows any origin to read responses
if name == ‘main’:
hug.API(name).http.serve(port=8000, debug=True)

The Secure Implementation

The vulnerability lies in the `debug=True` flag which exposes sensitive traceback data to the client upon failure. Furthermore, the lack of middleware allows wildcard CORS by default or via omission. The fix implements `CORSMiddleware` with a strict origin whitelist to prevent unauthorized cross-domain requests and explicitly sets `debug=False` to ensure the API fails gracefully without leaking the underlying system architecture.

import hug
from hug.middleware import CORSMiddleware
api = hug.API(name)
SECURE: Explicit CORS whitelist and production-ready server config
api.http.add_middleware(CORSMiddleware(api, allow_origins=[‘https://trusted-app.com’]))
@hug.get(‘/cmd’)
def exec_info():
return {‘status’: ‘authenticated’}
if name == ‘main’:
# Disable debug and use a production WSGI server like Gunicorn in real scenarios
api.http.serve(port=8000, debug=False)