SQL injection vulnerability found in the module “PayPal Official Module” (aka paypal) for PrestaShop from 3.12.0 to 3.16.3. (3.16.4 fix the issue) allow a remote attacker to gain privileges.

Summary

Description

Up to 3.16.3 (3.16.4 fix the issue), a sensitive SQL call in file ipn.php can be executed with a trivial http call and exploited to forge a blind SQL injection through the POST or GET submitted variable receiver_email.

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

  • Technical and personal data leaks
  • Obtain admin access
  • Remove all data of the linked PrestaShop
  • Display sensitives tables to front-office to unlock potential admin’s ajax scripts of modules protected by token on the ecosystem

Patch

diff --git a/ipn.php b/ipn.php
index 45525e99..e7808233 100644
--- a/ipn.php
+++ b/ipn.php
@@ -255,5 +255,5 @@ public function getResult()
     }
 } elseif (Tools::isSubmit('custom') && (int)Configuration::get('PAYPAL_PAYMENT_METHOD') == HSS) {
     $custom = Tools::jsonDecode(Tools::getValue('custom'), true);
-    Db::getInstance()->insert('paypal_hss_email_error', array('id_cart' => $custom['id_cart'], 'email' => Tools::getValue('receiver_email')));
+    Db::getInstance()->insert('paypal_hss_email_error', array('id_cart' => (int) $custom['id_cart'], 'email' => pSQL(Tools::getValue('receiver_email', ''))));
 }

See also

You can also install an adhoc module that verify and patch if necessary the vulnerability by following this knowledge base.

Other recommendations

  • It’s recommended to upgrade the module beyond 3.16.3.
  • 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_ by a new longer arbitrary prefix. Nevertheless, be warned that this is useless against blackhats with DBA senior skill 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 these set of rules.

Timeline

Date Action
2023-03-28 TouchWeb.fr discover the vulnerability during an audit
2023-03-28 The author verify the scope of versions
2023-03-28 Request a CVE ID
2023-03-28 Inform PayPal and PrestaShop
2023-03-31 Publish this security advisory