Contact Form 7 Style <= 3.1.9 - Cross-Site Request Forgery to Stored Cross-Site Scripting

Description

Due to the lack of sanitization and lack of nonce protection on the custom CSS feature, an attacker could craft a request to inject malicious JavaScript on a site using the plugin. If an attacker successfully tricked a site’s administrator into clicking a link or attachment, then the request could be sent and the CSS settings would be successfully updated to include malicious JavaScript.