The Strong Testimonials plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'platform_user_photo' Custom Field in all versions up to, and including, 3.3.11 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires that an administrator has added custom text fields named 'platform' and 'platform_user_photo' to a public testimonial submission form, as the plugin does not reserve those internal metadata keys.