Zennoxa Shield
Rules / Python
SHIELD-PY-012

Flask debug mode enabled

highPythonCWE-94CVSS 7.5

What it detects

Running Flask in debug mode in production exposes an interactive debugger.

How to fix

Disable debug mode in production. Use environment variables to control debug settings.

Vulnerable — Shield flags thisapp.py
from flask import Flask

app = Flask(__name__)

@app.route("/")
def index():
    return "hello"

if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)
Fixed — scans cleanapp.py
import os
from flask import Flask

app = Flask(__name__)

@app.route("/")
def index():
    return "hello"

if __name__ == "__main__":
    app.run(debug=os.environ.get("FLASK_DEBUG") == "1")

Both snippets are verified against the shipped scanner: the vulnerable one triggers SHIELD-PY-012, the fixed one does not.

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SHIELD-PY-012: Flask debug mode enabled — Zennoxa Shield