Class: Arachni::Checks::ResponseSplitting

Inherits:
Arachni::Check::Base show all
Defined in:
components/checks/active/response_splitting.rb

Overview

HTTP Response Splitting check.

Constant Summary

Constants included from Arachni::Check::Auditor

Arachni::Check::Auditor::DOM_ELEMENTS_WITH_INPUTS, Arachni::Check::Auditor::ELEMENTS_WITH_INPUTS, Arachni::Check::Auditor::FILE_SIGNATURES, Arachni::Check::Auditor::FILE_SIGNATURES_PER_PLATFORM, Arachni::Check::Auditor::Format, Arachni::Check::Auditor::SOURCE_CODE_SIGNATURES_PER_PLATFORM

Constants included from Arachni

BANNER, Arachni::Cookie, Form, Header, JSON, Link, LinkTemplate, NestedCookie, Severity, UIForm, UIInput, VERSION, WEBSITE, WIKI, XML

Instance Attribute Summary

Attributes included from Arachni::Check::Auditor

#framework, #page

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Arachni::Check::Base

#browser_cluster, #clean_up, elements, exempt_platforms, has_exempt_platforms?, has_platforms?, #initialize, platforms, #plugins, prefer, #preferred, preferred, #prepare, #session, supports_platforms?

Methods included from Arachni::Check::Auditor

#audit, #audit_differential, #audit_signature, #audit_timeout, #audited, #audited?, #buffered_audit, #each_candidate_dom_element, #each_candidate_element, has_timeout_candidates?, #http, #initialize, #log, #log_issue, #log_remote_file, #log_remote_file_if_exists, #match_and_log, #max_issues, #preferred, reset, #skip?, timeout_audit_run, #trace_taint, #with_browser, #with_browser_cluster

Methods inherited from Arachni::Component::Base

author, description, fullname, #shortname, shortname, shortname=, version

Methods included from Arachni::Component::Output

#depersonalize_output, #depersonalize_output?, #intercept_print_message

Methods included from UI::Output

#caller_location, #debug?, #debug_level, #debug_level_1?, #debug_level_2?, #debug_level_3?, #debug_level_4?, #debug_off, #debug_on, #disable_only_positives, #error_buffer, #error_log_fd, #error_logfile, #has_error_log?, #included, #log_error, #mute, #muted?, #only_positives, #only_positives?, #print_bad, #print_debug, #print_debug_backtrace, #print_debug_exception, #print_debug_level_1, #print_debug_level_2, #print_debug_level_3, #print_debug_level_4, #print_error, #print_error_backtrace, #print_exception, #print_info, #print_line, #print_ok, #print_status, #print_verbose, #reroute_to_file, #reroute_to_file?, reset_output_options, #set_error_logfile, #unmute, #verbose?, #verbose_off, #verbose_on

Methods included from Arachni::Component::Utilities

#read_file

Methods included from Utilities

#available_port, available_port_mutex, #bytes_to_kilobytes, #bytes_to_megabytes, #caller_name, #caller_path, #cookie_decode, #cookie_encode, #cookies_from_file, #cookies_from_parser, #cookies_from_response, #exception_jail, #exclude_path?, #follow_protocol?, #form_decode, #form_encode, #forms_from_parser, #forms_from_response, #full_and_absolute_url?, #generate_token, #get_path, #hms_to_seconds, #html_decode, #html_encode, #include_path?, #links_from_parser, #links_from_response, #normalize_url, #page_from_response, #page_from_url, #parse_set_cookie, #path_in_domain?, #path_too_deep?, #port_available?, #rand_port, #random_seed, #redundant_path?, #regexp_array_match, #remove_constants, #request_parse_body, #seconds_to_hms, #skip_page?, #skip_path?, #skip_resource?, #skip_response?, #to_absolute, #uri_decode, #uri_encode, #uri_parse, #uri_parse_query, #uri_parser, #uri_rewrite

Methods included from Arachni

URI, collect_young_objects, #get_long_win32_filename, jruby?, null_device, profile?, windows?

Constructor Details

This class inherits a constructor from Arachni::Check::Base

Class Method Details

.infoObject


48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
# File 'components/checks/active/response_splitting.rb', line 48

def self.info
    {
        name:        'Response Splitting',
        description: %q{
Injects arbitrary and checks if any of them end up in the response header.
},
        elements:    ELEMENTS_WITH_INPUTS,
        author:      'Tasos "Zapotek" Laskos <[email protected]> ',
        version:     '0.2.3',

        issue:       {
            name:            %q{Response Splitting},
            description:     %q{
HTTP response splitting occurs when untrusted data is inserted into the response
headers without any sanitisation.

If successful, this allows cyber-criminals to essentially split the HTTP response
in two.

This is abused by cyber-criminals injecting CR (Carriage Return -- `/r`)
and LF (Line Feed -- `\n`) characters which will then form the split. If the CR
or LF characters are not processed by the server then it cannot be exploited.

Along with these characters, cyber-criminals can then construct their own
arbitrary response headers and body which would then form the second response.
The second response is entirely under their control, allowing for a number of
other attacks.
},
            references:  {
                'SecuriTeam' => 'http://www.securiteam.com/securityreviews/5WP0E2KFGK.html',
                'OWASP'      => 'https://www.owasp.org/index.php/HTTP_Response_Splitting'
            },
            tags:            %w(response splitting injection header),
            cwe:             20,
            severity:        Severity::HIGH,
            remedy_guidance: %q{
It is recommended that untrusted data is never used to form the contents of the
response header.

Where any untrusted source is required to be used in the response headers, it is
important to ensure that any hazardous characters (`/r`, `/n` and potentially
others) are sanitised prior to being used.

This is especially important when setting cookie values, redirecting, etc..
},
        }
    }
end

Instance Method Details

#runObject


19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
# File 'components/checks/active/response_splitting.rb', line 19

def run
    header_name = "X-CRLF-Safe-#{random_seed}"

    # the header to inject...
    # what we will check for in the response header
    # is the existence of the "x-crlf-safe" field.
    # if we find it it means that the attack was successful
    # thus site is vulnerable.
    header = "\r\n#{header_name}: no"

    # try to inject the headers into all vectors
    # and pass a block that will check for a positive result
    audit(
        header,
        submit: {
            follow_location:   false,
            response_max_size: 0
        }
    ) do |response, element|
        next if response.headers[header_name].to_s.downcase != 'no'

        log(
            vector:   element,
            response: response,
            proof:    response.headers_string[/#{header_name}.*$/i]
        )
    end
end