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

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.

PoC

The PoC will be displayed once the issue has been remediated