Class: Brakeman::CheckFileAccess

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

Overview

Checks for user input in methods which open or manipulate files

Direct Known Subclasses

CheckSendFile

Constant Summary

Constants inherited from BaseCheck

BaseCheck::CONFIDENCE

Constants included from Util

Util::ALL_PARAMETERS, Util::COOKIES, Util::PARAMETERS, Util::PATH_PARAMETERS, Util::QUERY_PARAMETERS, Util::REQUEST_ENV, Util::REQUEST_PARAMETERS, Util::REQUEST_PARAMS, Util::SESSION

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, #initialize, #process_call, #process_cookies, #process_default, #process_if, #process_params

Methods included from Util

#array?, #call?, #camelize, #contains_class?, #context_for, #cookies?, #false?, #file_by_name, #file_for, #hash?, #hash_access, #hash_insert, #hash_iterate, #integer?, #node_type?, #number?, #params?, #pluralize, #regexp?, #request_env?, #request_value?, #result?, #set_env_defaults, #sexp?, #string?, #symbol?, #table_to_csv, #true?, #truncate_table, #underscore

Methods included from ProcessorHelper

#class_name, #process_all, #process_module

Methods inherited from SexpProcessor

#error_handler, #in_context, #initialize, #process, #process_dummy, #scope

Constructor Details

This class inherits a constructor from Brakeman::BaseCheck

Instance Method Details

#process_result(result) ⇒ Object 



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# File 'lib/brakeman/checks/check_file_access.rb', line 28

def process_result result
  return if duplicate? result
  add_result result
  call = result[:call]
  file_name = call.first_arg

  if match = has_immediate_user_input?(file_name)
    confidence = CONFIDENCE[:high]
  elsif match = has_immediate_model?(file_name)
    match = Match.new(:model, match)
    confidence = CONFIDENCE[:med]
  elsif tracker.options[:check_arguments] and
    match = include_user_input?(file_name)

    #Check for string building in file name
    if call?(file_name) and (file_name.method == :+ or file_name.method == :<<)
      confidence = CONFIDENCE[:high]
    else
      confidence = CONFIDENCE[:low]
    end
  end

  if match
    case match.type
    when :params
      message = "Parameter"
    when :cookies
      message = "Cookie"
    when :request
      message = "Request"
    when :model
      message = "Model attribute"
    else
      message = "User input"
    end

    message << " value used in file name"

    warn :result => result,
      :warning_type => "File Access",
      :message => message,
      :confidence => confidence,
      :code => call,
      :user_input => match.match
  end
end

#run_check ⇒ Object 



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# File 'lib/brakeman/checks/check_file_access.rb', line 10

def run_check
  Brakeman.debug "Finding possible file access"
  methods = tracker.find_call :targets => [:Dir, :File, :IO, :Kernel, :"Net::FTP", :"Net::HTTP", :PStore, :Pathname, :Shell], :methods => [:[], :chdir, :chroot, :delete, :entries, :foreach, :glob, :install, :lchmod, :lchown, :link, :load, :load_file, :makedirs, :move, :new, :open, :read, :readlines, :rename, :rmdir, :safe_unlink, :symlink, :syscopy, :sysopen, :truncate, :unlink]

  methods.concat tracker.find_call :target => :YAML, :methods => [:load_file, :parse_file]

  Brakeman.debug "Finding calls to load()"
  methods.concat tracker.find_call :target => false, :method => :load

  Brakeman.debug "Finding calls using FileUtils"
  methods.concat tracker.find_call :target => :FileUtils

  Brakeman.debug "Processing found calls"
  methods.each do |call|
    process_result call
  end
end