Bulk Page Generator < 2.5.8 - Authenticated (Contributor+) Stored Cross-Site Scripting via Post Title

Description

The Lpagery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via post titles in versions up to, and including, 2.5.7. This is due to insufficient input sanitization and output escaping in the lpagery_add_filter_text_template_post() function, which is hooked to admin_footer and echoes the raw post_title of the post referenced by the ?lpagery_template query parameter directly inside a JavaScript single-quoted string literal, without esc_js(), esc_html(), or any other encoding. 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 higher-privileged user (such as an administrator) accesses an admin page with the ?lpagery_template=<post_id> parameter pointing at the attacker's post.