Is Relevanssi safe? Known vulnerabilities and latest version

The Relevanssi – A Better Search plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'comment' parameter in all versions up to, and including, 4.28.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the site to have both the comment indexing and comment highlighting options enabled, and the payload only fires when a visitor reaches a singular page via a Relevanssi search-result permalink carrying the highlight query parameter.

Deserialization of Untrusted Data vulnerability in Christoph Vielgrader Relevanssi relevanssi allows Object Injection.This issue affects Relevanssi : from n/a through 4.28.4.

The Relevanssi – A Better Search plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 4.28.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This is only exploitable when the administrator has configured a non-empty value for the "Allowable tags in excerpts" setting, such as the default example value of <p><a><strong>, as the prefix-matching regex must have an allowable tag whose name is a prefix of the injected tag name.

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.

The Relevanssi WordPress plugin before 4.26.0, Relevanssi Premium WordPress plugin before 2.29.0 do not sanitize and escape a parameter before using it in a SQL statement, allowing contributor and above roles to perform SQL injection attacks

The Relevanssi – A Better Search plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Excerpt Highlights in all versions up to, and including, 4.24.5 (Free) and 2.27.6 (Premium) due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Relevanssi – A Better Search plugin for WordPress is vulnerable to time-based SQL Injection via the cats and tags query parameters in all versions up to, and including, 4.24.4 (Free) and <= 2.27.5 (Premium) due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries to already existing queries that can be used to extract sensitive information from the database.

The Relevanssi – A Better Search plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the highlights functionality in all versions up to, and including, 4.24.3 (Free) and <= 2.27.4 (Premium), due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page via the search results.

In the process of testing the Relevanssi WordPress plugin before 4.23.1, a vulnerability was found that allows you to implement Stored XSS on behalf of the Contributor+ by embedding malicious script, which entails account takeover backdoor

The Relevanssi – A Better Search plugin for WordPress is vulnerable to Information Exposure in all versions up to, and including, 4.22.2 (Free) and 2.25.1 (Premium) via the relevanssi_do_query() due to insufficient limitations on the posts that are returned when searching. This makes it possible for unauthenticated attackers to extract potentially sensitive information from password protected posts.

The Relevanssi – A Better Search plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the relevanssi_update_counts() function in all versions up to, and including, 4.22.1. This makes it possible for unauthenticated attackers to execute expensive queries on the application that could lead into DOS.

The Relevanssi – A Better Search plugin for WordPress is vulnerable to CSV Injection in all versions up to, and including, 4.22.1. This makes it possible for unauthenticated attackers to embed untrusted input into exported CSV files, which can result in code execution when these files are downloaded and opened on a local system with a vulnerable configuration.

The Relevanssi – A Better Search plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the relevanssi_export_log_check() function in all versions up to, and including, 4.22.0 (Free) and 2.25.0 (Premium). This makes it possible for unauthenticated attackers to export the query log data. The vendor has indicated that they may look into adding a capability check for proper authorization control, however, this vulnerability is theoretically patched as is.

The Relevanssi WordPress plugin before 4.22.0, Relevanssi Premium WordPress plugin before 2.25.0 allows any unauthenticated user to read draft and private posts via a crafted request

Cross-site scripting (XSS) vulnerability in the Relevanssi plugin before 3.3.8 for WordPress allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.