What happened
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.
Affected versions
DearFlip – PDF Flipbook, 3D Flipbook, PDF embed, PDF viewer: 0 through 2.4.30 (semver) Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.