A/B Testing for WordPress <= 1.18.2 - Authenticated (Contributor+) Stored Cross-Site Scripting

Description

The A/B Testing for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'ab-testing-for-wp/ab-test-block' block in all versions up to, and including, 1.18.2 due to insufficient input sanitization and output escaping on the 'id' parameter. 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.