B201: flask_debug_true

B201: Test for use of flask app with debug set to true

Running Flask applications in debug mode results in the Werkzeug debugger being enabled. This includes a feature that allows arbitrary code execution. Documentation for both Flask [1] and Werkzeug [2] strongly suggests that debug mode should never be enabled on production systems.

Operating a production server with debug mode enabled was the probable cause of the Patreon breach in 2015 [3].

>> Issue: A Flask app appears to be run with debug=True, which exposes
the Werkzeug debugger and allows the execution of arbitrary code.
   Severity: High   Confidence: High
      Location: examples/flask_debug.py:10
      9 #bad
      10    app.run(debug=True)

New in version 0.15.0.