In the module “Ask for a Quote - Convert to order, messaging system” (askforaquote) for PrestaShop, an anonymous user can perform SQL injection before 5.4.3. Release 5.4.3 fixed this security issue.

Summary

  • CVE ID: CVE-2023-27843
  • Published at: 2023-04-25
  • Advisory source: Friends-Of-Presta.org
  • Platform: PrestaShop
  • Product: askforaquote
  • Impacted release: < 5.4.3
  • Product author: Presta FABRIQUE
  • Weakness: CWE-89
  • Severity: critical (9.8)

Description

Up to 5.4.2, a sensitive SQL call in class QuotesProduct::deleteProduct() can be executed with a trivial http call and exploited to forge a blind SQL injection through the POST or GET submitted “item_id” variable.

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

Proof of concept

curl -v -X POST -d 'action=delete_from_cart&item_id=2_9%3Bdelete+from+0test+where+1%23' 'https://preprod.XXXXX/module/askforaquote/QuotesCart'

Patch

--- v5.4.1/modules/askforaquote/classes/QuotesProduct.php
+++ v5.4.2/modules/askforaquote/classes/QuotesProduct.php
@@ -160,9 +160,9 @@ class QuotesProductCart extends ObjectMo
         $row = Db::getInstance()->getRow(
             'SELECT qp.`quantity`, qp.`id_product_attribute`
             FROM `' . _DB_PREFIX_ . 'quotes_product` qp
-            WHERE qp.`id_product` = ' . pSQL($id_product) . '
+            WHERE qp.`id_product` = ' . (int) $id_product . '
             AND qp.`id_quote` LIKE "' . pSQL($id_quote) . '"
-            AND qp.`id_product_attribute` = ' . pSQL($id_product_attribute)
+            AND qp.`id_product_attribute` = ' . (int) $id_product_attribute
         );
@@ -211,16 +211,16 @@ class QuotesProductCart extends ObjectMo
                 }
             }
 
-            if ((int)$current_qty < 0) {
+            if ((int) $current_qty < 0) {
                 return $this->deleteProduct($id_product, $row['id_product_attribute']);
             }
 
-            //update current product in cart
+            // update current product in cart
             $update = Db::getInstance()->execute(
                 'UPDATE `' . _DB_PREFIX_ . 'quotes_product`
-                SET `quantity` = ' . pSQL($current_qty) . ', `date_upd` = "' . pSQL(date('Y-m-d H:i:s', time())) . '"
-                WHERE `id_product` = ' . pSQL($id_product) . ' AND `id_quote` LIKE "' . pSQL($id_quote) .
-                '" AND `id_product_attribute` = ' . pSQL($id_product_attribute) . '
+                SET `quantity` = ' . (int) $current_qty . ', `date_upd` = "' . pSQL(date('Y-m-d H:i:s', time())) . '"
+                WHERE `id_product` = ' . (int) $id_product . ' AND `id_quote` LIKE "' . pSQL($id_quote) .
+                '" AND `id_product_attribute` = ' . (int) $id_product_attribute . '
                 LIMIT 1'
             );
@@ -543,15 +542,15 @@ class QuotesProductCart extends ObjectMo
         /* Product deletion */
         $result = Db::getInstance()->execute(
             'DELETE FROM `' . _DB_PREFIX_ . 'quotes_product`
-            WHERE `id_product` = ' . pSQL($id_product) . '
+            WHERE `id_product` = ' . (int) $id_product . '
             AND `id_quote` LIKE "' . pSQL($this->id_quote) . '"
-            AND `id_product_attribute` = ' . pSQL($id_product_attribute)
+            AND `id_product_attribute` = ' . (int) $id_product_attribute
         );
 
         if ($result) {
             return true;
         }
        //$this->update(true);
 
         return false;
     }

Other recommendations

  • It’s recommended to upgrade the module beyond 5.4.2.
  • 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 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 these set of rules.

Timeline

Date Action
2022-10-09 Issue discovered during a code review by 202 ecommerce and TouchWeb
2023-02-12 Request a CVE ID
2023-02-28 Contact the author
2023-03-01 The author confirm the issue
2023-03-17 Propose 30 days before disclosure
2023-03-19 The author confirm a fix release in progress
2023-03-22 The author published the release 5.4.2
2023-04-25 Publication of this security advisory