Tipsen

The Dear Flipbook – PDF Flipbook, 3D Flipbook, PDF embed, PDF viewer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'post content (class attribute of .dvcss element)' parameter in all versions up to, and including, 2.4.30 due to insufficient input sanitization and output escaping. 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 payload is embedded as a Base64-encoded JSON object in a CSS class name on a Custom HTML block; the frontend parseCSSElements() function decodes it client-side with atob() and JSON.parse() and renders the logo property as raw HTML, meaning no server-side or client-side sanitization intercepts the malicious script before DOM insertion.

The Dear Flipbook – PDF Flipbook, 3D Flipbook, PDF embed, PDF viewer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'post content (Custom HTML block inner HTML)' parameter in all versions up to, and including, 2.4.30 due to insufficient input sanitization and output escaping. 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. A Contributor-level attacker can insert a crafted .df-element div with data-df-lightbox='thumb' via a Custom HTML block, whose inner HTML is passed as the title argument to parseThumbs() at render time, enabling both innerHTML injection into a span element and attribute breakout via an onerror handler on a constructed img element.

**Name of the Vulnerable Software and Affected Versions** WP Statistics versions prior to 14.16.9 **Description** Insufficient input sanitization and output escaping allow unauthenticated attackers to perform Stored Cross-Site Scripting. Attackers can inject arbitrary web scripts that execute when a user accesses an affected page. The injection is possible via the `/wp-statistics/v2/hit` REST endpoint, where a base64-encoded `page uri` POST parameter overrides the sanitized REQUEST URI, enabling a malicious `utm campaign` value to bypass security checks and be stored in the database. This is facilitated by the fact that the required signature is exposed on the public homepage. **Recommendations** Update to a version newer than 14.16.8. Restrict access to the `/wp-statistics/v2/hit` REST endpoint to minimize the risk of exploitation.