The WP HTML Author Bio WordPress plugin through 1.2.0 does not sanitise the HTML allowed in the Bio of users, allowing them to use malicious JavaScript code, which will be executed when anyone visit a post in the frontend made by such user. As a result, user with a role as low as author could perform Cross-Site Scripting attacks against users, which could potentially lead to privilege escalation when an admin view the related post/s.
Published October 11, 2021.