Blocksy <= 2.1.30 - Authenticated (Contributor+) Stored Cross-Site Scripting via `blocksy_meta` Fields

The Blocksy theme for WordPress is vulnerable to Stored Cross-Site Scripting via the `blocksy_meta` metadata fields in all versions up to, and including, 2.1.30 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.