The Broken Link Checker plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Author URL / Link Log in all versions up to, and including, 2.4.13 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. Exploitation requires an administrator to perform the plugin's standard dismiss-and-recheck workflow on a link submitted by the attacker via the WordPress comment author URL field, after which the attacker's HTTP server issues a redirect to a URL containing an HTML/JavaScript payload that is stored verbatim in the link log.