ITERAS <= 1.8.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

The ITERAS plugin for WordPress is vulnerable to Stored Cross-Site Scripting via multiple shortcodes (iteras-ordering, iteras-signup, iteras-paywall-login, iteras-selfservice) in all versions up to and including 1.8.2. This is due to insufficient input sanitization and output escaping in the combine_attributes() function. The function directly concatenates shortcode attribute values into JavaScript code within <script> tags using double-quoted string interpolation (line 489: '"'.$key.'": "'.$value.'"') without any escaping. An attacker can break out of the JavaScript string context by including a double-quote character in a shortcode attribute value and inject arbitrary JavaScript. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.