In the module “Marketing automation multicanal” (cartsguru) up to versions 2.4.2 from Carts Guru for PrestaShop, a guest can perform SQL injection in affected versions.

Summary

  • CVE ID: CVE-2023-39642
  • Published at: 2023-08-29
  • Platform: PrestaShop
  • Product: cartsguru
  • Impacted release: <= 2.4.2 [considered to be “truly” fixed on 2.4.3 - see note below]
  • Product author: Carts Guru
  • Weakness: CWE-89
  • Severity: critical (9.8)

Description

The method CartsGuruCatalogModuleFrontController::display() and the ajax script controllers14/catalog.php has sensitive SQL calls that can be executed with a trivial http call and exploited to forge a SQL injection.

Note : The author has deleted from its module the files that have been suffering from critical vulnerabilities for months, BUT did not set them to be “auto-deleted” during upgrades. Therefore, there are likely merchants out there with older versions who have updated their modules, thinking they are safe. However, there is nothing safe about this, since past upgrades did not auto-delete the implicated files. To ensure everyone has a “safe version”, we decided to mark all versions up to 2.4.3 as impacted by this issue.

WARNING : This exploit is actively used to deploy webskimmer to massively steal credit cards.

One of these exploits 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: none
  • User interaction: none
  • Scope: unchanged
  • Confidentiality: high
  • Integrity: high
  • Availability: high

Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Possible malicious usage

  • Obtain admin access
  • Remove data from the associated PrestaShop
  • Copy/paste data from sensitive tables to FRONT to expose tokens and unlock admins’ ajax scripts
  • Rewrite SMTP settings to hijack emails

Proof of concept

curl -v 'https://preprod.XX/modules/cartsguru/controllers14/catalog.php?cartsguru_catalog_limit=1;select(0x73656C65637420736C656570283432293B)INTO@a;prepare`b`from@a;execute`b`;--'
curl -v 'https://preprod.XX/?fc=module&module=cartsguru&controller=catalog&cartsguru_catalog_limit=1;select(0x73656C65637420736C656570283432293B)INTO@a;prepare`b`from@a;execute`b`;--'

Patch from 1.4.19

These files do not exist if you started working with Cartsguru beyond version 2.X BUT if you worked with them BEFORE 2.X versions - you should own it.

--- 1.4.19/controllers14/catalog.php
+++ XXXXXX/controllers14/catalog.php
if ($isMultiStoreSupported) {
    $id_shop = (int)Context::getContext()->shop->id;

    $sql .= ' JOIN ' . _DB_PREFIX_ . 'product_shop s ON p.id_product = s.id_product WHERE id_shop = ' . $id_shop;
    $sqlTotal .= ' JOIN ' . _DB_PREFIX_ . 'product_shop s ON p.id_product = s.id_product WHERE id_shop = ' . $id_shop;
}

// Set limit and offset
-$sql .= ' LIMIT ' . pSQL($limit) . ' OFFSET ' . pSQL($offset);
+$sql .= ' LIMIT ' . (int) $limit . ' OFFSET ' . (int) $offset;

--- 1.4.19/controllers/front/catalog.php
+++ XXXXXX/controllers/front/catalog.php
        if (CartsGuruHelper::isMultiStoreSupported()) {
            $id_shop = (int)Context::getContext()->shop->id;

            $sql .= ' WHERE id_shop = ' . $id_shop;
            $sqlTotal .= ' WHERE id_shop = ' . $id_shop;
        }
        // Set limit and offset
-       $sql .= ' LIMIT ' . pSQL($limit) . ' OFFSET ' . pSQL($offset);
+       $sql .= ' LIMIT ' . (int) $limit . ' OFFSET ' . (int) $offset;

Other recommendations

  • It’s recommended to upgrade to the latest version of the module cartsguru.
  • To help improve the security of your PrestaShop installation, we recommend upgrading to the latest version. One of the benefits of upgrading is that it will disable the use of multiquery executions (separated by semicolons). However, please be aware that this will not protect your shop against SQL injection attacks that use the UNION clause to steal data. Additionally, it’s important to note that PrestaShop includes a function called pSQL, which includes a strip_tags function. This helps protect your shop against Stored XSS (also known as XSS T2) of Category 1. If a pSQL function is missing, it could potentially expose your project to critical Stored XSS vulnerabilities due to edge cases. Therefore, it’s crucial to ensure that all relevant functions are properly implemented and used consistently throughout your project.
  • Change the default database prefix ps_ with a new longer, arbitrary prefix. Nevertheless, be warned that this is useless against blackhats with DBA senior skills because of a design vulnerability in DBMS
  • Activate OWASP 942’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
2022-10-11 Issue discovered during a code review by TouchWeb.fr
2022-10-12 Author contacted and provided a patch
2023-04-18 Contact PrestaShop Addons security Team to confirm versions scope by author
2023-04-19 Request a CVE ID
2023-05-09 PrestaShop Addons confirms versions scopes
2023-05-24 Author provide a patch which auto-delete files from old versions
2023-08-25 Received CVE ID
2023-08-29 Publish this security advisory