Simple Post <= 1.1 - Authenticated Stored Cross-Site Scripting (XSS)

Proof of Concept

1. Install WordPress 5.7.2
2. Install and activate Simple Post
3. Navigate to Settings >> Simple Post and enter the XSS payload into the Text input field.
4. Click Update Options.
5. You will observe that the payload successfully got stored into the database and when you are triggering the same functionality at that time JavaScript payload is executing successfully and we are getting a pop-up.
6. Payload Used: "><script>alert(document.cookie)</script>