This article is a part of our Vulnerability Database (back to index)
Cross-Site Request Forgery occurrences in Visual Css Style Editor
The WaspThemes Visual CSS Style Editor (aka yellow-pencil-visual-theme-customizer) plugin before 7.2.1 for WordPress allows yp_option_update CSRF, as demonstrated by use of yp_remote_get to obtain admin access. (2019-05-13, CVE-2019-11886)
Why Cross-Site Request Forgery can be dangerous
The absence of Anti-CSRF tokens may lead to a Cross-Site Request Forgery attack that can result in executing a specific application action as another logged in user, e.g. steal their account by changing their email and password or silently adding a new admin user account when executed from the administrator account.
The attacker may copy one of your web application forms, e.g. email/password change form.
The webpage will contain a form with the exact set of fields as the original application but with input values already provided and the submit button replaced with a Javascript code causing auto-submission. When the page is accessed the form will be immediately submitted and page contents replaced with a valid content or a redirect to your original application.
One of your application users who is already logged in can be then tricked to navigate to such malicious page e.g. by clicking a link in a phishing email, and the pre-populated form content will be submitted to your application like it would be submitted by your user.