Vulnerabilidades do Comesio Relevanssi – A Better Search

The Relevanssi – A Better Search plugin for WordPress is vulnerable to Reflected Cross-Site Scripting in versions up to, and including, 4.28.1 via the 's', 'post_types', and 'orderby' request parameters. This is due to insufficient input sanitization and output escaping in the relevanssi_debug_array() function in lib/debug.php, which dumps user-supplied query variables through print_r() inside a <pre> block without HTML escaping. The debug path is enabled by supplying the relevanssi_debug=on request parameter when the administrator has previously enabled the 'Debugging mode' setting; the gate itself is a configuration check with no capability, nonce, or logged-in check (the vendor explicitly suppresses nonce verification on that line). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.

The plugin provides an Admin Search page that allows users with the `edit_posts` capability to run Relevanssi searches from the WordPress dashboard. The AJAX handler accepts a URL-encoded `args` parameter, parses it into a `WP_Query`, and then passes user-controlled taxonomy query data into Relevanssi's taxonomy restriction builder. The taxonomy value is sanitized as text but is not parameterized for SQL before being interpolated into a term taxonomy lookup query. This allows an authenticated contributor-level attacker to inject SQL through the Admin Search AJAX request and execute time-based blind SQL injection against the WordPress database.