Master Slider < 3.10.0 - Contributor+ Stored XSS via ms_layer Shortcode

Description

The plugin is vulnerable to Stored Cross-Site Scripting via the plugin's 'ms_layer' shortcode due to insufficient input sanitization and output escaping on the 'css_id' user supplied attribute. 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