The Clearfy Cache – WordPress optimization plugin, Minify HTML, CSS & JS, Defer plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.4.0. This is due to missing nonce validation on the "wbcr_upm_change_flag" function. This makes it possible for unauthenticated attackers to disable plugin/theme update notifications via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.