Class: Contrast::Agent::Assess::Policy::Trigger::ReflectedXss

Inherits:
Object
  • Object
show all
Defined in:
lib/contrast/agent/assess/policy/trigger/reflected_xss.rb

Overview

This acts a trigger to handle the special cases of the Tilt library gem. Reflected XSS data may come into the trigger methods from these classes.

Constant Summary collapse

NODE_HASH = 
{
    'class_name' => 'Tilt::Template',
    'instance_method' => true,
    'method_name' => 'render',
    'method_visibility' => 'public',
    'action' => 'CUSTOM',
    'source' => 'O,P0',
    'target' => 'R',
    'patch_class' => 'Contrast::Agent::Assess::Policy::Trigger::ReflectedXss',
    'patch_method' => 'xss_tilt_trigger'
}.cs__freeze
TEMPLATE_PROPAGATION_NODE = 
Contrast::Agent::Assess::Policy::PropagationNode.new(NODE_HASH)

Class Method Summary collapse

Class Method Details

.xss_tilt_trigger(trigger_node, _source, object, ret, *args) ⇒ Object

Parameters:

  • trigger_node (Contrast::Agent::Assess::Policy::MethodPolicy) —

    the node that governs this propagation event.

  • _source (Object) —

    the source of the propagation

  • object (Object) —

    the object to which the source is being appended

  • args (Array) —

    the arguments to the method

  • ret (Object) —

    the return value of the method



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# File 'lib/contrast/agent/assess/policy/trigger/reflected_xss.rb', line 33

def xss_tilt_trigger trigger_node, _source, object, ret, *args
  return unless (properties = Contrast::Agent::Assess::Tracker.properties!(ret))

  scope = args[0]
  erb_template_prerender = object.instance_variable_get(:@data)
  interpolated_inputs = []
  handle_binding_variables(scope, erb_template_prerender, ret, properties, interpolated_inputs)
  handle_local_variables(args, erb_template_prerender, ret, properties, interpolated_inputs)
  event_data = Contrast::Agent::Assess::Events::EventData.new(TEMPLATE_PROPAGATION_NODE,
                                                              ret,
                                                              erb_template_prerender,
                                                              ret,
                                                              interpolated_inputs)
  properties.build_event(event_data)
  properties.copy_from(erb_template_prerender, ret, 0)
  unless interpolated_inputs.empty?
    current_event = properties.event
    interpolated_inputs.each do |input|
      input_properties = Contrast::Agent::Assess::Tracker.properties(input)
      next unless input_properties&.event

      current_event.parent_events << input_properties.event
    end
  end

  if Contrast::Agent::Assess::Tracker.tracked?(ret)
    finding = Contrast::Agent::Assess::Policy::TriggerMethod.build_finding(trigger_node,
                                                                           ret,
                                                                           erb_template_prerender,
                                                                           ret,
                                                                           interpolated_inputs)
    Contrast::Agent::Assess::Policy::TriggerMethod.report_finding(finding) if finding
  end

  ret
end