Class: Brakeman::CheckXMLDoS

Inherits:
BaseCheck show all
Defined in:
lib/brakeman/checks/check_xml_dos.rb

Constant Summary

Constants inherited from BaseCheck

BaseCheck::CONFIDENCE

Constants included from Util

Util::ALL_COOKIES, Util::ALL_PARAMETERS, Util::COOKIES, Util::COOKIES_SEXP, Util::DIR_CONST, Util::LITERALS, Util::PARAMETERS, Util::PARAMS_SEXP, Util::PATH_PARAMETERS, Util::QUERY_PARAMETERS, Util::REQUEST_COOKIES, Util::REQUEST_ENV, Util::REQUEST_PARAMETERS, Util::REQUEST_PARAMS, Util::REQUEST_REQUEST_PARAMETERS, Util::SAFE_LITERAL, Util::SESSION, Util::SESSION_SEXP, Util::SIMPLE_LITERALS

Constants inherited from SexpProcessor

SexpProcessor::VERSION

Instance Attribute Summary

Attributes inherited from BaseCheck

#tracker, #warnings

Attributes inherited from SexpProcessor

#context, #env, #expected

Instance Method Summary collapse

Methods inherited from BaseCheck

#add_result, inherited, #initialize, #process_array, #process_call, #process_cookies, #process_default, #process_dstr, #process_if, #process_params

Methods included from Messages

#msg, #msg_code, #msg_cve, #msg_file, #msg_input, #msg_lit, #msg_plain, #msg_version

Methods included from Util

#all_literals?, #array?, #block?, #call?, #camelize, #class_name, #constant?, #contains_class?, #cookies?, #dir_glob?, #false?, #hash?, #hash_access, #hash_insert, #hash_iterate, #hash_values, #integer?, #kwsplat?, #literal?, #make_call, #node_type?, #number?, #params?, #pluralize, #rails_version, #recurse_check?, #regexp?, #remove_kwsplat, #request_headers?, #request_value?, #result?, #safe_literal, #safe_literal?, #safe_literal_target?, #set_env_defaults, #sexp?, #simple_literal?, #string?, #string_interp?, #symbol?, #template_path_to_name, #true?, #underscore

Methods included from ProcessorHelper

#current_file, #process_all, #process_all!, #process_call_args, #process_call_defn?, #process_class, #process_module

Methods inherited from SexpProcessor

#in_context, #initialize, #process, processors, #scope

Constructor Details

This class inherits a constructor from Brakeman::BaseCheck

Instance Method Details

#has_workaround? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/brakeman/checks/check_xml_dos.rb', line 37

def has_workaround?
  tracker.find_call(target: :"ActiveSupport::XmlMini", method: :backend=).any? do |match|
    arg = match[:call].first_arg
    if string? arg
      value = arg.value
      value == 'Nokogiri' or value == 'LibXML'
    end
  end
end

#run_check ⇒ Object 



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# File 'lib/brakeman/checks/check_xml_dos.rb', line 8

def run_check
  version = rails_version

  fix_version = case
                when version_between?("2.0.0", "3.2.21")
                  "3.2.22"
                when version_between?("4.1.0", "4.1.10")
                  "4.1.11"
                when version_between?("4.2.0", "4.2.1")
                  "4.2.2"
                when version_between?("4.0.0", "4.0.99")
                  "4.2.2"
                else
                  return
                end

  return if has_workaround?

  message = msg(msg_version(version), " is vulnerable to denial of service via XML parsing ", msg_cve("CVE-2015-3227"), ". Upgrade to ", msg_version(fix_version))

  warn :warning_type => "Denial of Service",
    :warning_code => :CVE_2015_3227,
    :message => message,
    :confidence => :medium,
    :gem_info => gemfile_or_environment,
    :link_path => "https://groups.google.com/d/msg/rubyonrails-security/bahr2JLnxvk/x4EocXnHPp8J",
    :cwe_id => [125]
end