SlimStat Analytics <= 5.1.3 - Authenticated (Subscriber+) Stored Cross-Site Scripting

The SlimStat Analytics plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'filter_array' parameter in all versions up to, and including, 5.1.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.