Fix TypeError in sessions -v and add an "unknown" platform class

lib/metasploit/framework/login_scanner/ssh.rb

@@ -165,12 +165,14 @@ def get_platform(proof)
             'aix'
           when /Win32|Windows/
             'windows'
-          when /Unknown command or computer name/
+          when /Unknown command or computer name/, /Line has invalid autocommand/
             'cisco-ios'
           when /unknown keyword/ # ScreenOS
             'juniper'
           when /JUNOS Base OS/ #JunOS
             'juniper'
+          else
+            'unknown'
           end
         end
 

lib/msf/base/serializer/readable_text.rb

@@ -768,8 +768,9 @@ def self.dump_sessions_verbose(framework, opts={})
       sess_checkin = "<none>"
       sess_registration = "No"
 
-      if session.respond_to?(:platform)
-        sess_type << " " + session.platform
+      # to_s is required incase something bugged earlier and .platform is nil
+      if session.respond_to?(:platform) && !session.platform.nil?
+        sess_type << " " + session.platform.to_s
       end
 
       if session.respond_to?(:last_checkin) && session.last_checkin

lib/msf/core/module/platform.rb

@@ -576,4 +576,15 @@ class Apple_iOS < Msf::Module::Platform
     Alias = "apple_ios"
   end
 
+  #
+  # Unknown
+  # This is a special case for when we're completely unsure of the
+  # platform, such as a crash or default case in code.  Only
+  # utilize this as a catch-all.
+  #
+  class Unknown < Msf::Module::Platform
+    Rank = 0 # safeguard with 0 since the platform is completely unknown
+    Alias = "unknown"
+  end
+
 end