In the module “Help Desk - Customer Support Management System” (helpdesk) up to version 2.4.0 from FME Modules for PrestaShop, a customer can upload .php files.

Summary

  • CVE ID: CVE-2024-34990
  • Published at: 2024-06-18
  • Platform: PrestaShop
  • Product: helpdesk
  • Impacted release: < 2.4.0 (2.4.0 fixed the vulnerability)
  • Product author: FME Modules
  • Weakness: CWE-434
  • Severity: critical (9.9)

Description

Methods HelpdeskHelpdeskModuleFrontController::submitTicket() and HelpdeskHelpdeskModuleFrontController::replyTicket() allow upload of .php files on a predictable path for connected customers, it will lead to a critical vulnerability CWE-94.

This exploit uses a PrestaShop front controller and most attackers can conceal the module controller’s path during the exploit, so you will never know within your conventional frontend logs that it exploits this vulnerability. You will only see “POST /” inside your conventional frontend logs. Activating the AuditEngine of mod_security (or similar) is the only way to get data to confirm this exploit.

CVSS base metrics

  • Attack vector: network
  • Attack complexity: low
  • Privilege required: low
  • User interaction: none
  • Scope: changed
  • Confidentiality: high
  • Integrity: high
  • Availability: high

Vector string: AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Possible malicious usage

  • Obtain admin access
  • Remove data from the associated PrestaShop
  • Steal data

Proof of concept

  1. Connect as customer
  2. Go to the customer ticket’s dashboard
  3. Submit a ticket or Reply to an existing one, with a .php file in attachment

Other recommendations

  • It’s recommended to upgrade to the latest version of the module helpdesk.
  • Activate OWASP 933’s rules on your WAF (Web application firewall), be warned that you will probably break your backoffice and you will need to pre-configure some bypasses against this set of rules.

Timeline

Date Action
2024-02-07 Issue discovered during a code review by TouchWeb.fr
2024-02-07 Contact PrestaShop Addons security Team to confirm version scope by author
2024-02-07 PrestaShop Addons security Team confirms version scope by author
2024-04-16 Author provide a patch
2024-05-15 Received CVE ID
2024-06-18 Publish this security advisory