Module: PWN::SAST::ReDOS

Defined in:
lib/pwn/sast/redos.rb

Overview

SAST Module used to identify Regular Expression DOS within source code. For more information, see: www.owasp.org/index.php/Regular_expression_Denial_of_Service_-_ReDoS

Constant Summary collapse

@@logger = 
PWN::Plugins::PWNLogger.create

Class Method Summary collapse

Class Method Details

.authors ⇒ Object

Author(s)

0day Inc. <[email protected]>



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# File 'lib/pwn/sast/redos.rb', line 130

public_class_method def self.authors
  "AUTHOR(S):
    0day Inc. <[email protected]>
  "
end

.help ⇒ Object

Display Usage for this Module



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# File 'lib/pwn/sast/redos.rb', line 138

public_class_method def self.help
  puts "USAGE:
    sast_arr = #{self}.scan(
      :dir_path => 'optional path to dir defaults to .',
      :git_repo_root_uri => 'optional http uri of git repo scanned'
    )

    #{self}.authors
  "
end

.scan(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SAST::ReDOS.scan(

dir_path: 'optional path to dir defaults to .'
git_repo_root_uri: 'optional http uri of git repo scanned'

)



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# File 'lib/pwn/sast/redos.rb', line 19

public_class_method def self.scan(opts = {})
  dir_path = opts[:dir_path]
  git_repo_root_uri = opts[:git_repo_root_uri].to_s.scrub
  result_arr = []
  logger_results = ''

  PWN::Plugins::FileFu.recurse_dir(dir_path: dir_path) do |entry|
    if File.file?(entry) && File.basename(entry) !~ /^pwn.+(html|json|db)$/ && File.basename(entry) !~ /\.JS-BEAUTIFIED$/ && entry !~ /test/i
      line_no_and_contents_arr = []
      entry_beautified = false

      if File.extname(entry) == '.js' && (`wc -l #{entry}`.split.first.to_i < 20 || entry.include?('.min.js') || entry.include?('-all.js'))
        js_beautify = `js-beautify #{entry} > #{entry}.JS-BEAUTIFIED`.to_s.scrub
        entry = "#{entry}.JS-BEAUTIFIED"
        entry_beautified = true
      end

      test_case_filter = "
        grep -Fin \
        -e '(a+)+' \
        -e '([a-zA-Z]+)*' \
        -e '(a|aa)+' \
        -e '(a|a?)+' \
        -e '(([a-z])' \
        -e '([a-zA-Z0-9])' \
        -e '(.*a)\{' #{entry}
      "

      str = `#{test_case_filter}`.to_s.scrub

      if str.to_s.empty?
        # If str length is >= 64 KB do not include results. (Due to Mongo Document Size Restrictions)
        logger_results = "#{logger_results}~" # Catching bugs is good :)
      else
        str = "1:Result larger than 64KB -> Size: #{str.to_s.length}.  Please click the \"Path\" link for more details." if str.to_s.length >= 64_000

        hash_line = {
          timestamp: Time.now.strftime('%Y-%m-%d %H:%M:%S.%9N %z').to_s,
          security_references: security_references,
          filename: { git_repo_root_uri: git_repo_root_uri, entry: entry },
          line_no_and_contents: '',
          raw_content: str,
          test_case_filter: test_case_filter
        }

        # COMMMENT: Must be a better way to implement this (regex is kinda funky)
        line_contents_split = str.split(/^(\d{1,}):|\n(\d{1,}):/)[1..-1]
        line_no_count = line_contents_split.length # This should always be an even number
        current_count = 0
        while line_no_count > current_count
          line_no = line_contents_split[current_count]
          contents = line_contents_split[current_count + 1]
          if Dir.exist?("#{dir_path}/.git") ||
             Dir.exist?('.git')

            repo_root = dir_path
            repo_root = '.' if Dir.exist?('.git')

            author = PWN::Plugins::Git.get_author(
              repo_root: repo_root,
              from_line: line_no,
              to_line: line_no,
              target_file: entry,
              entry_beautified: entry_beautified
            )
          else
            author = 'N/A'
          end
          hash_line[:line_no_and_contents] = line_no_and_contents_arr.push(
            line_no: line_no,
            contents: contents,
            author: author
          )

          current_count += 2
        end
        result_arr.push(hash_line)
        logger_results = "#{logger_results}x" # Seeing progress is good :)
      end
    end
  end
  logger_banner = "http://#{Socket.gethostname}:8808/doc_root/pwn-#{PWN::VERSION.to_s.scrub}/#{to_s.scrub.gsub('::', '/')}.html"
  if logger_results.empty?
    @@logger.info("#{logger_banner}: No files applicable to this test case.\n")
  else
    @@logger.info("#{logger_banner} => #{logger_results}complete.\n")
  end
  result_arr
rescue StandardError => e
  raise e
end

.security_references ⇒ Object

Used primarily to map NIST 800-53 Revision 4 Security Controls web.nvd.nist.gov/view/800-53/Rev4/impact?impactName=HIGH to PWN Exploit & Static Code Anti-Pattern Matching Modules to Determine the level of Testing Coverage w/ PWN.



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# File 'lib/pwn/sast/redos.rb', line 116

public_class_method def self.security_references
  {
    sast_module: self,
    section: 'PROTECTION OF INFORMATION AT REST',
    nist_800_53_uri: 'https://csrc.nist.gov/Projects/risk-management/sp800-53-controls/release-search#/control/?version=5.1&number=SC-28',
    cwe_id: '1333',
    cwe_uri: 'https://cwe.mitre.org/data/definitions/1333.html'
  }
rescue StandardError => e
  raise e
end