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 pandas as pd
import re
import requests
import pickle


class LinkBuilder:

    def __init__(self, tweets, href):
        self.tweets = tweets
        self.href = href
        self.unprocessed = []
        self.next = []

        self.data = list(pd.read_pickle(tweets)[2])

        for e in self.data:
            urls = re.findall('http[s]?://(?:[a-zA-Z]|[0-9]|[$-&(-_@.&+]|[!*\(\),]|(?:%[0-9a-fA-F][0-9a-fA-F]))+',
                              str(e))
            self.unprocessed.append(urls)

    def ntweets(self):
        return len(self.data)

    def nlinks(self):
        return len(self.unprocessed)

    def __iter__(self):
        return self

    def __next__(self):

        if len(self.unprocessed) == 0:
            raise StopIteration

        while len(self.next) == 0:
            self.next = self.unprocessed.pop()
            if len(self.next) == 0:
                print('No links in this tweet..')

        curr = self.next.pop()

        try:
            final = requests.get(curr).url

            if self.href in final:
                return final
            else:
                return self.__next__()

        except Exception as e:
            print('Unable to fetch link %s' % curr)
            return self.__next__()


pkls = [
    # '../twitter_scraper/verge_tweets_2018-10-03.pkl',
    # '../twitter_scraper/Gizmodo_tweets_2018-10-03.pkl',
    # '../twitter_scraper/WIRED_tweets_2018-10-03.pkl'
]

hrefs = [
    # 'https://www.theverge.com/',
    # 'https://gizmodo.com/',
    # 'https://www.wired.com/'
]

dsnames = [
    # 'theverge',
    # 'gizomodo',
    # 'wired'
]

backup_interval = 10

for tweets, href, fname in zip(pkls, hrefs, dsnames):
    i = 1

    print('Working on %s, href = %s' % (tweets, href))
    links = LinkBuilder(tweets=tweets, href=href)
    fetched = []
    file = fname + '.pkl'

    for link in links:
        print("Found new link! (#%s) : %s" % (i, link))
        fetched.append(link)

        if i % backup_interval == 0:
            print('Saving links so far into file %s..' % file)
            with open(file, 'wb') as f:
                pickle.dump(fetched, f)

        i += 1


```

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

  A) CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  B) CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
  C) CWE-209: Generation of Error Message Containing Sensitive Information
  D) CWE-295: Improper Certificate Validation
  E) CWE-20: Improper Input Validation
  F) CWE-732: Incorrect Permission Assignment for Critical Resource
Answer: E