Correct Prices <= 1.0 - Reflected Cross-Site Scripting via PHP_SELF Parameter

The Correct Prices plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the $_SERVER['PHP_SELF'] variable in versions up to and including 1.0. This is due to the correct_prices_page() function echoing $_SERVER['PHP_SELF'] into a form's action attribute without any input sanitization or output escaping (such as esc_url() or esc_attr()). Because PHP_SELF reflects attacker-controlled path-info appended to the script URL, an attacker can break out of the attribute and inject arbitrary markup. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.