http_auth_detect

2013-06-10T23:02:10
ID W3AF:8D9F41ED1BD87499CA6F510570D90E37
Type w3af
Reporter andresriancho
Modified 2018-05-10T17:23:42

Description

This plugin greps every page and finds responses that indicate that the resource requires authentication.

Plugin type

Grep

Options

This plugin doesn't have any user configured options.

Source

For more information about this plugin and the associated tests, there's always the source code to understand exactly what's under the hood:
Plugin source code
Unittest source code

Dependencies

This plugin has no dependencies.

                                        
                                            """
http_auth_detect.py

Copyright 2006 Andres Riancho

This file is part of w3af, http://w3af.org/ .

w3af is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation version 2 of the License.

w3af is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with w3af; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

"""
import re

import w3af.core.controllers.output_manager as om
import w3af.core.data.kb.knowledge_base as kb
import w3af.core.data.constants.severity as severity
import w3af.core.data.parsers.parser_cache as parser_cache

from w3af.core.controllers.exceptions import BaseFrameworkException
from w3af.core.controllers.plugins.grep_plugin import GrepPlugin
from w3af.core.data.kb.info import Info
from w3af.core.data.kb.vuln import Vuln


class http_auth_detect(GrepPlugin):
    """
    Find responses that indicate that the resource requires auth.

    :author: Andres Riancho (andres.riancho@gmail.com)
    """

    def __init__(self):
        GrepPlugin.__init__(self)

        self._auth_uri_regex = re.compile('.*://[\w%]*?:[\w%]*?@[\w\.]{3,40}')

    def grep(self, request, response):
        """
        Finds 401 or authentication URIs like http://user:pass@domain.com/

        :param request: The HTTP request object.
        :param response: The HTTP response object
        :return: None
        """
        # If I have a 401 code, and this URL wasn't already reported...
        if response.get_code() == 401:

            # Doing this after the other if in order to be faster.
            already_reported = [i.get_url().get_domain_path() for i in
                                kb.kb.get('http_auth_detect', 'auth')]
            if response.get_url().get_domain_path() not in already_reported:

                # Perform all the work in this method
                self._analyze_401(response)

        elif response.is_text_or_html():

            # I get here for "normal" HTTP 200 responses
            self._find_auth_uri(response)

    def _find_auth_uri(self, response):
        """
        Analyze a 200 response and report any findings of http://user:pass@domain.com/
        :return: None
        """
        #
        #   Analyze the HTTP URL
        #
        if self._url_has_auth(response.get_uri()):
            # An authentication URI was found!
            desc = ('The resource: "%s" has a user and password in'
                    ' the URI.')
            desc %= response.get_uri()
            v = Vuln('Basic HTTP credentials', desc, severity.HIGH,
                     response.id, self.get_name())

            v.set_url(response.get_url())
            v.add_to_highlight(response.get_uri().url_string)

            kb.kb.append(self, 'userPassUri', v)
            om.out.vulnerability(v.get_desc(), severity=v.get_severity())

        #
        #   Analyze the HTTP response body
        #
        url_list = []
        try:
            document_parser = parser_cache.dpc.get_document_parser_for(response)
        except BaseFrameworkException, e:
            msg = 'Failed to find a suitable document parser. Exception: "%s"'
            om.out.debug(msg % e)
        else:
            parsed_references, re_references = document_parser.get_references()
            url_list.extend(parsed_references)
            url_list.extend(re_references)

        for url in url_list:

            if self._url_has_auth(url):

                desc = ('The resource: "%s" has a user and password in the'
                        ' body. The offending URL is: "%s".')
                desc %= (response.get_url(), url)
                
                v = Vuln('Basic HTTP credentials', desc,
                         severity.HIGH, response.id, self.get_name())

                v.set_url(response.get_url())
                v.add_to_highlight(url.url_string)

                kb.kb.append(self, 'userPassUri', v)
                om.out.vulnerability(v.get_desc(), severity=v.get_severity())

    def _url_has_auth(self, url):
        if '@' not in url.url_string:
            return False

        if not self._auth_uri_regex.match(url.url_string):
            return False

        return True

    def _get_realm(self, response):
        for key in response.get_headers():
            if key.lower() == 'www-authenticate':
                realm = response.get_headers()[key]
                return realm
        
        return None
        
    def _report_no_realm(self, response):
        # Report this strange case
        desc = ('The resource: "%s" requires authentication (HTTP Code'
                ' 401) but the www-authenticate header is not present.'
                ' This requires human verification.')
        desc %= response.get_url()
        i = Info('Authentication without www-authenticate header', desc,
                 response.id, self.get_name())
        i.set_url(response.get_url())

        kb.kb.append(self, 'non_rfc_auth', i)
        om.out.information(i.get_desc())
        
    def _analyze_401(self, response):
        """
        Analyze a 401 response and report it.
        :return: None
        """
        realm = self._get_realm(response)
        
        if realm is None:
            self._report_no_realm(response)
            return
        
        insecure = response.get_url().get_protocol() == 'http'
        vuln_severity = severity.HIGH if insecure else severity.LOW
        
        desc = 'The resource: "%s" requires HTTP authentication'
        if insecure:
            desc += (' over a non-encrypted channel, which allows'
                     ' potential intruders to sniff traffic and capture'
                     ' valid credentials.')
        else:
            desc += '.'
        
        desc += ' The received authentication realm is: "%s".'
        desc = desc % (response.get_url(), realm)
        
        # Report the common case, were a realm is set.
        if 'ntlm' in realm.lower():
            
            v = Vuln('NTLM authentication', desc,
                     vuln_severity, response.id, self.get_name())

        else:
            v = Vuln('HTTP Basic authentication', desc,
                     vuln_severity, response.id, self.get_name())

        v.set_url(response.get_url())
        v['message'] = realm
        v.add_to_highlight(realm)

        kb.kb.append(self, 'auth', v)
        om.out.information(v.get_desc())

    def get_long_desc(self):
        """
        :return: A DETAILED description of the plugin functions and features.
        """
        return """
        This plugin greps every page and finds responses that indicate that the
        resource requires authentication.
        """