The WC Product Table Lite plugin for WordPress is vulnerable to CSS Injection in versions up to, and including, 5.6.0 via the 'laptop_scroll_offset' shortcode attribute exposed through the unauthenticated wcpt_ajax() AJAX handler. The handler is registered for wp_ajax_nopriv_wcpt_ajax, JSON-decodes attacker-supplied attributes, only allowlists key names (not values), applies a preg_replace that strips only [ ] < >, and passes the value through do_shortcode into wcpt_style__sticky_sidebar(), where it is interpolated verbatim into inline CSS ('top: {$top}px;' and 'max-height: calc(100vh - {$top}px);') with no numeric casting or CSS escaping. This makes it possible for unauthenticated attackers to inject arbitrary CSS declarations and rules on pages rendering a product table with sticky sidebar enabled, which can be leveraged for data exfiltration (via attribute-selector + background-image URLs), UI redressing, and phishing that bypasses CSPs permitting inline styles.
Attack Parameters
Impact Assessment
CVSS Vector v3.1