Class: Brakeman::CheckSingleQuotes

Inherits:
BaseCheck
  • Object
show all
Defined in:
lib/brakeman/checks/check_single_quotes.rb

Overview

Checks for versions which do not escape single quotes. https://groups.google.com/d/topic/rubyonrails-security/kKGNeMrnmiY/discussion

Constant Summary collapse

RACK_UTILS = 
Sexp.new(:colon2, Sexp.new(:const, :Rack), :Utils)

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ CheckSingleQuotes

Returns a new instance of CheckSingleQuotes.



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# File 'lib/brakeman/checks/check_single_quotes.rb', line 11

def initialize *args
  super
  @inside_erb = @inside_util = @inside_html_escape = @uses_rack_escape = false
end

Instance Method Details

#process_call(exp) ⇒ Object

Look for

Rack::Utils.escape_html


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# File 'lib/brakeman/checks/check_single_quotes.rb', line 97

def process_call exp
  if @inside_html_escape and exp.target == RACK_UTILS and exp.method == :escape_html
    @uses_rack_escape = true
  else
    process exp.target if exp.target
  end

  exp
end

#process_class(exp) ⇒ Object

Look for

class ERB


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# File 'lib/brakeman/checks/check_single_quotes.rb', line 58

def process_class exp
  if exp.class_name == :ERB
    @inside_erb = true
    process_all exp.body
    @inside_erb = false
  end

  exp
end

#process_defn(exp) ⇒ Object

Look for

def html_escape


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# File 'lib/brakeman/checks/check_single_quotes.rb', line 84

def process_defn exp
  if @inside_util and exp.method_name == :html_escape
    @inside_html_escape = true
    process_all exp.body
    @inside_html_escape = false
  end

  exp
end

#process_module(exp) ⇒ Object

Look for

module Util


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# File 'lib/brakeman/checks/check_single_quotes.rb', line 71

def process_module exp
  if @inside_erb and exp.module_name == :Util
    @inside_util = true
    process_all exp.body
    @inside_util = false
  end

  exp
end

#run_check ⇒ Object 



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# File 'lib/brakeman/checks/check_single_quotes.rb', line 16

def run_check
  return if uses_rack_escape?

  if version_between? '2.0.0', '2.3.14'
    message = msg("All Rails 2.x versions do not escape single quotes ", msg_cve("CVE-2012-3464"))
  else
    message = msg(msg_version(rails_version), " does not escape single quotes ", msg_cve("CVE-2012-3464"), ". Upgrade to ")

    case
    when version_between?('3.0.0', '3.0.16')
      message << msg_version('3.0.17')
    when version_between?('3.1.0', '3.1.7')
      message << msg_version('3.1.8')
    when version_between?('3.2.0', '3.2.7')
      message << msg_version('3.2.8')
    else
      return
    end
  end

  warn :warning_type => "Cross-Site Scripting",
    :warning_code => :CVE_2012_3464,
    :message => message,
    :confidence => :medium,
    :gem_info => gemfile_or_environment,
    :link_path => "https://groups.google.com/d/topic/rubyonrails-security/kKGNeMrnmiY/discussion",
    :cwe_id => [79]
end

#uses_rack_escape? ⇒ Boolean

Process initializers to see if they use workaround by replacing Erb::Util.html_escape

Returns:

  • (Boolean) 


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# File 'lib/brakeman/checks/check_single_quotes.rb', line 47

def uses_rack_escape?
  @tracker.initializers.each do |_name, src|
    process src
  end

  @uses_rack_escape
end