CVE-2024-34716: PrestaShop cross-site scripting via customer contact form in FO, through file upload

Only PrestaShops with customer-thread feature flag enabled are impacted, starting from PrestaShop 8.1.0.

The impact is substantial, when the customer thread feature flag is enabled, through the front-office contact form, a hacker can upload a malicious file containing an XSS that will be executed when an admin opens the attached file in back office.

Consequence: the script injected can access the session and the security token, which allows it to perform any authenticated action in the scope of the administrator’s right.