Class: Brakeman::CheckFileAccess
- Inherits:
-
BaseCheck
- Object
- SexpProcessor
- BaseCheck
- Brakeman::CheckFileAccess
- Defined in:
- lib/brakeman/checks/check_file_access.rb
Overview
Checks for user input in methods which open or manipulate files
Direct Known Subclasses
Constant Summary
Constants inherited from BaseCheck
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
Instance Attribute Summary
Attributes inherited from BaseCheck
Attributes inherited from SexpProcessor
Instance Method Summary collapse
-
#called_on_tempfile?(file_name) ⇒ Boolean
When using Tempfile, there is no risk of unauthorized file access, since Tempfile adds a unique string onto the end of every provided filename, and ensures that the filename does not already exist in the system.
- #process_result(result) ⇒ Object
- #run_check ⇒ Object
- #sanitized?(file) ⇒ Boolean
- #temp_file_method?(exp) ⇒ Boolean
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
#called_on_tempfile?(file_name) ⇒ Boolean
When using Tempfile, there is no risk of unauthorized file access, since Tempfile adds a unique string onto the end of every provided filename, and ensures that the filename does not already exist in the system.
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# File 'lib/brakeman/checks/check_file_access.rb', line 71 def called_on_tempfile? file_name call?(file_name) && file_name.target == s(:const, :Tempfile) end |
#process_result(result) ⇒ Object
[View source]
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# File 'lib/brakeman/checks/check_file_access.rb', line 29 def process_result result return unless original? result call = result[:call] file_name = call.first_arg return if called_on_tempfile?(file_name) || sanitized?(file_name) if match = has_immediate_user_input?(file_name) confidence = :high elsif match = has_immediate_model?(file_name) match = Match.new(:model, match) confidence = :medium elsif tracker.[: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 = :high else confidence = :weak end end if match and not temp_file_method? match.match = msg(msg_input(match), " used in file name") warn :result => result, :warning_type => "File Access", :warning_code => :file_access, :message => , :confidence => confidence, :code => call, :user_input => match, :cwe_id => [22] end end |
#run_check ⇒ Object
[View source]
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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] methods.concat tracker.find_call :target => nil, :method => [:open] 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 |
#sanitized?(file) ⇒ Boolean
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# File 'lib/brakeman/checks/check_file_access.rb', line 75 def sanitized? file call?(file) && call?(file.target) && class_name(file.target.target) == :"ActiveStorage::Filename" end |
#temp_file_method?(exp) ⇒ Boolean
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# File 'lib/brakeman/checks/check_file_access.rb', line 81 def temp_file_method? exp if call? exp return true if exp.call_chain.include? :tempfile params? exp.target and exp.method == :path end end |