WP Real IP-based Access Control <= 1.3.1 - Unauthenticated Stored XSS via acl_ctrl_addr

The WP Real IP-based Access Control WordPress plugin through 1.3.1 does not perform any capability or nonce checks before storing one of its option values, and does not escape that value on output on its settings page, allowing unauthenticated users to store arbitrary JavaScript that executes in the context of any administrator who views the page.