The xmlrpc attacks blocker plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 1.0, via the 'X-Forwarded-For' HTTP header. This is due to the plugin trusting and logging attacker-controlled IP header data and rendering debug log entries without output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator views the debug log page.