Real-time Find And Replace Cross-Site Request Forgery

An issue was discovered in the Real-Time Find and Replace plugin before 4.0.2 for WordPress. The far_options_page function did not do any nonce verification, allowing for requests to be forged on behalf of an administrator. The find and replace rules could be updated with malicious JavaScript, allowing for that be executed later in the victims browser. (2020-05-28, CVE-2020-13641)

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.