In versions from 1.6.0.10 and before 1.7.8.7 PrestaShop is subject to an SQL injection vulnerability which can be chained to call PHP’s Eval function on attacker input.

Summary

  • CVE ID: CVE-2022-31181
  • Published at: 2022-07-25
  • Advisory source: PrestaShop
  • Platform: PrestaShop
  • Product: PrestaShop
  • Impacted release: >=1.6.0.10, 1.7.8.7
  • Product author: PrestaShop
  • Weakness: CWE-89, CWE-95
  • Severity: critical (9.8)

Description

Eval injection possible if the shop is vulnerable to an SQL injection. The problem is fixed in version 1.7.8.7. Users are advised to upgrade. Users unable to upgrade may delete the MySQL Smarty cache feature.

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

According to PrestaShop team, this vulnerability has been exploited to add a malicious code.

“After the attackers successfully gained control of a shop, they injected a fake payment form on the front-office checkout page. In this scenario, shop customers might enter their credit card information on the fake form, and unknowingly send it to the attackers.”

Patch

Delete the MySQL Smarty cache feature by removing these lines in the file config/smarty.config.inc.php lines 43-46 (PrestaShop 1.7) or 40-43 (PrestaShop 1.6):

--- a/config/smarty.config.inc.php
+++ a/config/smarty.config.inc.php
@@ -40,10 +40,6 @@ $smarty->use_sub_dirs = true;
 $smarty->setConfigDir(_PS_SMARTY_DIR_.'configs');
 $smarty->caching = false;
 
-if (Configuration::get('PS_SMARTY_CACHING_TYPE') == 'mysql') {
-    include _PS_CLASS_DIR_.'Smarty/SmartyCacheResourceMysql.php';
-    $smarty->caching_type = 'mysql';
-}
 $smarty->force_compile = (Configuration::get('PS_SMARTY_FORCE_COMPILE') == _PS_SMARTY_FORCE_COMPILE_) ? true : false;
 $smarty->compile_check = (Configuration::get('PS_SMARTY_FORCE_COMPILE') >= _PS_SMARTY_CHECK_COMPILE_) ? true : false;
 $smarty->debug_tpl = _PS_ALL_THEMES_DIR_.'debug.tpl';

Or upgrade up to 1.7.8.7.

Other recommendations

  • 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.
  • Configure CSP headers (content security policies) by listing externals domains allowed to load assets (such as js files) or being called in XHR transactions (Ajax).
  • 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.