Post Meta Data Manager <= 1.2.3 - Authenticated (Contributor+) Stored Cross-Site Scripting

The Post Meta Data Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘$meta_key’ parameter in all versions up to, and including, 1.2.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.