system: You are an expert security code reviewer. You will be shown a source code file along with a multi-select question listing several CWE (Common Weakness Enumeration) categories. Your task is to identify which of the listed CWEs are present in the code.

OUTPUT FORMAT: Respond with the letter(s) of all correct options, sorted alphabetically and comma-separated, wrapped in a single \boxed{...}. Examples: `\boxed{A}` for one correct, `\boxed{A,C}` for two, `\boxed{A,C,E}` for three. Output the boxed answer ONLY -- no explanation, no other text.

user: ```python
import logging
from google.appengine.ext import db


class Configuration(db.Model):
    arduino_phone_number = db.StringProperty()
    appengine_phone_number = db.StringProperty()
    twilio_sid = db.StringProperty()
    twilio_token = db.StringProperty()

def get_configuration():
    existing = Configuration.all().fetch(1)
    if len(existing) == 0:
        return Configuration(
            arduino_phone_number = "",
            appengine_phone_number = "",
            twilio_sid = "",
            twilio_token = ""
        )

    return existing[0]

def set_arduino_phone_number(arduino_phone_number):
    configuration = get_configuration()
    logging.info("Writing Arduino Phone Number to datastore: %s" % arduino_phone_number)
    configuration.arduino_phone_number = arduino_phone_number
    configuration.put()

def get_arduino_phone_number():
    return get_configuration().arduino_phone_number

def set_appengine_phone_number(appengine_phone_number):
    configuration = get_configuration()
    logging.info("Writing AppEngine Phone Number to datastore: %s" % appengine_phone_number)
    configuration.appengine_phone_number = appengine_phone_number
    configuration.put()

def get_appengine_phone_number():
    return get_configuration().appengine_phone_number

def set_twilio_sid(twilio_sid):
    configuration = get_configuration()
    logging.info("Writing Twilio Application SID to datastore: %s" % twilio_sid)
    configuration.twilio_sid = twilio_sid
    configuration.put()

def get_twilio_sid():
    return get_configuration().twilio_sid

def set_twilio_token(twilio_token):
    configuration = get_configuration()
    logging.info("Writing Twilio Authentication Token to datastore: %s" % twilio_token)
    configuration.twilio_token = twilio_token
    configuration.put()

def get_twilio_token():
    return get_configuration().twilio_token


class Flight(db.Model):
    code = db.StringProperty()

def get_flights():
    return Flight.all()

def add_flight(code):
    flight = Flight(code = code)
    flight.put()

def remove_flight(code):
    for flight in Flight.all().filter("code =", code).fetch():
      flight.delete()
```

Which of the following CWE vulnerability categories are present in this code? Multiple options may be correct.

  A) CWE-116: Improper Encoding or Escaping of Output
  B) CWE-209: Generation of Error Message Containing Sensitive Information
  C) CWE-312: Cleartext Storage of Sensitive Information
  D) CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  E) CWE-295: Improper Certificate Validation
  F) CWE-730: OWASP Top Ten 2004 Category A9 - Denial of Service
Answer: C