Zoho Campaigns <= 2.0.7 - Cross-Site Request Forgery via zcwc_optin_save

The Zoho Campaigns plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.7. This is due to missing or incorrect nonce validation on the zcwc_optin_save function. This makes it possible for unauthenticated attackers to update the optin setting via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.