The Testimonial Slider WordPress plugin before 2.3.8 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)
The Testimonial Slider WordPress plugin before 2.3.7 does not properly ensure that a user has the necessary capabilities to edit certain sensitive Testimonial Slider WordPress plugin before 2.3.7 settings, making it possible for users with at least the Author role to edit them.