The Simple Download Counter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'sdcmenu' shortcode in all versions up to, and including, 2.3. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes, specifically the 'text' and 'cat' attributes. The 'text' attribute is output directly into HTML content on line 159 without any escaping (e.g., eschtml()). The 'cat' attribute is used unescaped in HTML class attributes on lines 135 and 157 without escattr(). 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.

The Simple Download Counter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcodes in versions up to, and including, 1.6 due to insufficient input sanitization and output escaping on user supplied attributes like 'before' and 'after'. This makes it possible for authenticated attackers, with contributor-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.