system: You are an expert security code reviewer. You will be shown a source code file along with a catalog of candidate CWE (Common Weakness Enumeration) categories with their official MITRE names. Your task is to list every distinct CWE from that catalog that is actually present in the code. The catalog is comprehensive for this dataset -- the answer is a (possibly small) subset of it.

OUTPUT FORMAT: Respond with a comma-separated list of CWE IDs in the form `CWE-N`, sorted in ascending numeric order, wrapped in a single \boxed{...}. Examples: `\boxed{CWE-79}` for one, `\boxed{CWE-22,CWE-79,CWE-327}` for three. Output the boxed answer ONLY -- no explanation, no other text.

user: ```python
# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import re


class CSSChecker(object):

  def __init__(self, input_api, output_api, file_filter=None):
    self.input_api = input_api
    self.output_api = output_api
    self.file_filter = file_filter

  def RunChecks(self):
    # We use this a lot, so make a nick name variable.
    def _collapseable_hex(s):
      return (len(s) == 6 and s[0] == s[1] and s[2] == s[3] and s[4] == s[5])

    def _is_gray(s):
      return s[0] == s[1] == s[2] if len(s) == 3 else s[0:2] == s[2:4] == s[4:6]

    def _remove_all(s):
      return _remove_grit(_remove_ats(_remove_comments(s)))

    def _remove_ats(s):
      return re.sub(re.compile(r'@\w+.*?{(.*{.*?})+.*?}', re.DOTALL), '\\1', s)

    def _remove_comments(s):
      return re.sub(re.compile(r'/\*.*?\*/', re.DOTALL), '', s)

    def _remove_grit(s):
      grit_reg = r'<if[^>]+>.*?<\s*/\s*if[^>]*>|<include[^>]+>'
      return re.sub(re.compile(grit_reg, re.DOTALL), '', s)

    def _rgb_from_hex(s):
      if len(s) == 3:
        r, g, b = s[0] + s[0], s[1] + s[1], s[2] + s[2]
      else:
        r, g, b = s[0:2], s[2:4], s[4:6]
      return int(r, base=16), int(g, base=16), int(b, base=16)

    def alphabetize_props(contents):
      errors = []
      for rule in re.finditer(r'{(.*?)}', contents, re.DOTALL):
        semis = map(lambda t: t.strip(), rule.group(1).split(';'))[:-1]
        rules = filter(lambda r: ': ' in r, semis)
        props = map(lambda r: r[0:r.find(':')], rules)
        if props != sorted(props):
          errors.append('    %s;\nExpected: %s' % (
                        ';\n    '.join(rules), ','.join(list(sorted(props)))))
      return errors

    def braces_have_space_before_and_nothing_after(line):
      return re.search(r'(?:^|\S){|{\s*\S+\s*$', line)

    def classes_use_dashes(line):
      # Intentionally dumbed down version of CSS 2.1 grammar for class without
      # non-ASCII, escape chars, or whitespace.
      m = re.search(r'\.(-?[_a-zA-Z0-9-]+).*[,{]\s*$', line)
      return (m and (m.group(1).lower() != m.group(1) or
                     m.group(1).find('_') >= 0))

    # Ignore single frames in a @keyframe, i.e. 0% { margin: 50px; }
    frame_reg = r'\s*\d+%\s*{\s*[_a-zA-Z0-9-]+:(\s*[_a-zA-Z0-9-]+)+\s*;\s*}\s*'

    def close_brace_on_new_line(line):
      return (line.find('}') >= 0 and re.search(r'[^ }]', line) and
              not re.match(frame_reg, line))

    def colons_have_space_after(line):
      return re.search(r'(?<!data):(?!//)\S[^;]+;\s*', line)

    def favor_single_quotes(line):
      return line.find('"') >= 0

    # Shared between hex_could_be_shorter and rgb_if_not_gray.
    hex_reg = (r'#([a-fA-F0-9]{3}|[a-fA-F0-9]{6})(?=[^_a-zA-Z0-9-]|$)'
               r'(?!.*(?:{.*|,\s*)$)')

    def hex_could_be_shorter(line):
      m = re.search(hex_reg, line)
      return (m and _is_gray(m.group(1)) and _collapseable_hex(m.group(1)))

    small_seconds = r'(?:^|[^_a-zA-Z0-9-])(0?\.[0-9]+)s(?!-?[_a-zA-Z0-9-])'

    def milliseconds_for_small_times(line):
      return re.search(small_seconds, line)

    def no_data_uris_in_source_files(line):
      return re.search(r'\(\s*\'?\s*data:', line)

    def one_rule_per_line(line):
      return re.search(r'[_a-zA-Z0-9-](?<!data):(?!//)[^;]+;\s*[^ }]\s*', line)

    any_reg = re.compile(r':(?:-webkit-)?any\(.*?\)', re.DOTALL)
    multi_sels = re.compile(r'(?:}[\n\s]*)?([^,]+,(?=[^{}]+?{).*[,{])\s*$',
                            re.MULTILINE)

    def one_selector_per_line(contents):
      errors = []
      for b in re.finditer(multi_sels, re.sub(any_reg, '', contents)):
        errors.append('    ' + b.group(1).strip().splitlines()[-1:][0])
      return errors

    def rgb_if_not_gray(line):
      m = re.search(hex_reg, line)
      return (m and not _is_gray(m.group(1)))

    def suggest_ms_from_s(line):
      ms = int(float(re.search(small_seconds, line).group(1)) * 1000)
      return ' (replace with %dms)' % ms

    def suggest_rgb_from_hex(line):
      suggestions = ['rgb(%d, %d, %d)' % _rgb_from_hex(h.group(1))
                     for h in re.finditer(hex_reg, line)]
      return ' (replace with %s)' % ', '.join(suggestions)

    def suggest_short_hex(line):
      h = re.search(hex_reg, line).group(1)
      return ' (replace with #%s)' % (h[0] + h[2] + h[4])

    hsl = r'hsl\([^\)]*(?:[, ]|(?<=\())(?:0?\.?)?0%'
    zeros = (r'^.*(?:^|\D)'
             r'(?:\.0|0(?:\.0?|px|em|%|in|cm|mm|pc|pt|ex|deg|g?rad|m?s|k?hz))'
             r'(?:\D|$)(?=[^{}]+?}).*$')

    def zero_length_values(contents):
      errors = []
      for z in re.finditer(re.compile(zeros, re.MULTILINE), contents):
        first_line = z.group(0).strip().splitlines()[0]
        if not re.search(hsl, first_line):
          errors.append('    ' + first_line)
      return errors

    added_or_modified_files_checks = [
        {
            'desc': 'Alphabetize properties and list vendor specific (i.e. '
                    '-webkit) above standard.',
            'test': alphabetize_props,
            'multiline': True,
        },
        {
            'desc': 'Start braces ({) end a selector, have a space before them '
                    'and no rules after.',
            'test': braces_have_space_before_and_nothing_after,
        },
        {
            'desc': 'Classes use .dash-form.',
            'test': classes_use_dashes,
        },
        {
            'desc': 'Always put a rule closing brace (}) on a new line.',
            'test': close_brace_on_new_line,
        },
        {
            'desc': 'Colons (:) should have a space after them.',
            'test': colons_have_space_after,
        },
        {
            'desc': 'Use single quotes (\') instead of double quotes (") in '
                    'strings.',
            'test': favor_single_quotes,
        },
        {
            'desc': 'Use abbreviated hex (#rgb) when in form #rrggbb.',
            'test': hex_could_be_shorter,
            'after': suggest_short_hex,
        },
        {
            'desc': 'Use milliseconds for time measurements under 1 second.',
            'test': milliseconds_for_small_times,
            'after': suggest_ms_from_s,
        },
        {
            'desc': 'Don\'t use data URIs in source files. Use grit instead.',
            'test': no_data_uris_in_source_files,
        },
        {
            'desc': 'One rule per line '
                    '(what not to do: color: red; margin: 0;).',
            'test': one_rule_per_line,
        },
        {
            'desc': 'One selector per line (what not to do: a, b {}).',
            'test': one_selector_per_line,
            'multiline': True,
        },
        {
            'desc': 'Use rgb() over #hex when not a shade of gray (like #333).',
            'test': rgb_if_not_gray,
            'after': suggest_rgb_from_hex,
        },
        {
            'desc': 'Make all zero length terms (i.e. 0px) 0 unless inside of '
                    'hsl() or part of @keyframe.',
            'test': zero_length_values,
            'multiline': True,
        },
    ]

    results = []
    affected_files = self.input_api.AffectedFiles(include_deletes=False,
                                                  file_filter=self.file_filter)
    files = []
    for f in affected_files:
      # Remove all /*comments*/, @at-keywords, and grit <if|include> tags; we're
      # not using a real parser. TODO(dbeam): Check alpha in <if> blocks.
      file_contents = _remove_all('\n'.join(f.new_contents))
      files.append((f.filename, file_contents))

    # Only look at CSS files for now.
    for f in filter(lambda f: f[0].endswith('.css'), files):
      file_errors = []
      for check in added_or_modified_files_checks:
        # If the check is multiline, it receieves the whole file and gives us
        # back a list of things wrong. If the check isn't multiline, we pass it
        # each line and the check returns something truthy if there's an issue.
        if ('multiline' in check and check['multiline']):
          check_errors = check['test'](f[1])
          if len(check_errors) > 0:
            # There are currently no multiline checks with ['after'].
            file_errors.append(
                '- %s\n%s' % (check['desc'], '\n'.join(check_errors).rstrip()))
        else:
          check_errors = []
          lines = f[1].splitlines()
          for lnum in range(0, len(lines)):
            line = lines[lnum]
            if check['test'](line):
              error = '    ' + line.strip()
              if 'after' in check:
                error += check['after'](line)
              check_errors.append(error)
          if len(check_errors) > 0:
            file_errors.append(
                '- %s\n%s' % (check['desc'], '\n'.join(check_errors)))
      if file_errors:
        results.append(self.output_api.PresubmitPromptWarning(
            '%s:\n%s' % (f[0], '\n\n'.join(file_errors))))

    if results:
      # Add your name if you're here often mucking around in the code.
      authors = ['dbeam@chromium.org']
      results.append(self.output_api.PresubmitNotifyResult(
          'Was the CSS checker useful? Send feedback or hate mail to %s.' %
          ', '.join(authors)))

    return results

```

Candidate CWE catalog (every CWE that appears anywhere in this dataset):
  - CWE-20: Improper Input Validation
  - CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  - CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
  - CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
  - CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  - CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
  - CWE-94: Improper Control of Generation of Code ('Code Injection')
  - CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
  - CWE-116: Improper Encoding or Escaping of Output
  - CWE-117: Improper Output Neutralization for Logs
  - CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
  - CWE-209: Generation of Error Message Containing Sensitive Information
  - CWE-215: Insertion of Sensitive Information Into Debugging Code
  - CWE-295: Improper Certificate Validation
  - CWE-312: Cleartext Storage of Sensitive Information
  - CWE-326: Inadequate Encryption Strength
  - CWE-327: Use of a Broken or Risky Cryptographic Algorithm
  - CWE-377: Insecure Temporary File
  - CWE-502: Deserialization of Untrusted Data
  - CWE-601: URL Redirection to Untrusted Site ('Open Redirect')
  - CWE-611: Improper Restriction of XML External Entity Reference
  - CWE-614: Sensitive Cookie in HTTPS Session Without 'Secure' Attribute
  - CWE-643: Improper Neutralization of Data within XPath Expressions ('XPath Injection')
  - CWE-730: OWASP Top Ten 2004 Category A9 - Denial of Service
  - CWE-732: Incorrect Permission Assignment for Critical Resource
  - CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
  - CWE-918: Server-Side Request Forgery (SSRF)
  - CWE-943: Improper Neutralization of Special Elements in Data Query Logic
  - CWE-1004: Sensitive Cookie Without 'HttpOnly' Flag
  - CWE-1333: Inefficient Regular Expression Complexity

List every distinct CWE from the catalog above that is actually present in this code.
Answer: CWE-1333