The Countdown Timer for WordPress Block Editor WordPress plugin through 1.0.5 does not validate and escape some of its block options before outputting them back in a page/post where the block is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.
The Countdown Timer for Elementor WordPress plugin before 1.3.7 does not sanitise and escape some parameters when outputting them on the page, which could allow users with a role as low as contributor to perform Cross-Site Scripting attacks.